Version 1.3 of the Kayak iPhone app is now available in the iTunes Store.

We’ve fixed a lot of bugs, and replaced the scrolling/wheel date selector with a calendar.

On the bug side of things, the app now crashes a lot less, the false “no internet connection” bug is fixed, and all of the disappearing results problems are fixed.

We hope you like the calendar for trip selection. You can swipe to pick you trip with a single stroke, or you can touch the start and end days of your trip. You can also adjust the end points of your trip by touching and dragging the start or end day. Picking a round trip can be done in one touch, whereas the old wheel-based selector needed at least six touches. More importantly, since it’s a calendar view, you can see the day of the week, and get a better “feel” of when your trip is.

Cinco de Mayo is a special day for Kayak. It is the day, back in 2004, when we launched our first (Alpha) site.

We had 13 employees, a T1 and two servers back then. As a corporate entity, we were less than 4 months old. Here’s what we looked like:

Since the dawn of civilization, mankind has wanted custom airport selection on Kayak flight search. And now, in the greatest human achievement since Stonehenge and the merger of Drakes and Hostess (”all your snack cakes are belong to us”), Kayak gives you what we call:

(wait for it)

“Kayak Custom Airports.”

Suppose you are Jay Leno, you are in Burbank and you want to fly to Paris. But you don’t like LAX or Long Beach airports. For most of the life of the known universe (13.5-14 billion earth years), you would have been COMPLETELY unable to find flights from BUR, ONT and OXR to CDG on Kayak.com with one click. But lo:

Not only can you search specific nearby airports that you care about, but check this out. Suppose you are a Harvard student named “Ken,” and you want to go to Paris for spring break with “Lana,” who is your pal at Northwestern, and “Bill,” who dropped out of Harvard to work at some software company. You can, in one search, find flights for all of you to take. Then, add in Kayak collaborative search (”Share results now” link in the upper left of the results page), and you can all look at the same results together, and pick three flights from Seattle, Chicago and Boston that arrive at Charles De Gaulle about the same time.

It’s something you can tell your grandchildren about. You were there when it happened.

We thought it would be interesting to see how the swine flu has affected user travel search patterns.

The data below shows the relative change in user search activity from last week to this week, to and from Mexico.

As I’m sure you know, what happens to you in high school will haunt you for the rest of your life. I was just chatting with Warren Buffett the other day. He’s still bitter about the Junior Spring Cotillion when Janey Neuman wouldn’t dance with him because she was taller than him. Well, it wasn’t THE Warren Buffett, the billionaire. It was my friend Warren Buffett the arborist. The point is that it COULD have been THE Warren Buffett the billionaire, and you would totally believe the story.*

I’ll let you in on a little secret. There are some of us here at Kayak who were not exactly popular in high school. So we built this great travel web site and now we fly around the world in gold-plated private jets, sipping Veuve Clicquot La Grande Dame 1990 and eating truffle sandwiches.**

But all we really want is to be popular, to be one of the cool kids. So, please, vote for us in the People’s Choice Webby Awards, Travel Category. Do it for all the poor Warren Buffetts who got dissed by Janey Neuman.

* OK, I made the whole thing up, I don’t even know anybody named Warren, or Buffett.

** I made that up too. We fly coach, drink Sunny-D and eat Double Chocolate Pop Tarts.***

*** OK, fine, everything in this post is fabricated, except for the Pop Tarts and the Webby Awards. Please vote for us.

We are really excited to announce that Kayak is now available for your iPhone and iPod in the Apple App Store. We’re selling it for the pretty much the best price possible: FREE.

That’s the most important part of this post. We have an iPhone app, if you have an iPhone and you travel, you should download it. The rest of this article is the story of how we made the iPhone app. If you are not a software developer, the intense boredom rays emitted from the information herein is likely to melt your temporal lobe. You’ll wake up in two or three hours with a face full of keyboard and a keyboard full of drool.

OK, now that all the “norms” have gone away, let’s get to it.

First, some background: a wicked long time ago, back in 2004, my old boss called me up and said “Hey, we’re starting a travel web site, come to Harvard Square for a meeting.” And I said, “That’s boring there are already like 12 travel web sites. And it’s raining and I don’t want to drive through Alewife.” And he said “Come on, it’s a good idea.” and I said “OK.” I think about four hours later I was signed up. Over the next few weeks, we put together a technology plan and team. At the time (remember, this was way, way long ago in 2004) I was really getting into Mac OS X, because for a Unix nerd like me, it was a dream come true. A solid Unix/BSD/Mach kernel, no worrying about configuring drivers, and a nice GUI. So one of the first things we decided to do was to decide to develop Kayak on Mac OS X. It took quite a bit of convincing my boss (Paul, our cofounder and CTO) and our VP of engineering (the other Paul), but they bought it. I’d worked with them both for about 13 years, on and off. I was even pushing that we should deploy the web site on Apple Xserves running OS X. Luckily, Paul #1 stopped me. That would have been a big problem. To make a short anecdote even longer, development on Mac has been a pretty good win for us, though as of today about half of the Kayak developers have gone over to using Ubuntu Linux.

That was a really long way of getting to the point that I’m kind of an Apple nut. When the iPhone came out, I bought one the second day it was available. (No, I didn’t wait in a long line. In fact there was no line at all.) When the iPhone developer program was announced, I was really excited to get started.

We applied to be part of the initial roll-out of iPhone developers, but so did 500 million other companies. It took us quite a while to get accepted into the iPhone Developer program, but it worked out for the better. While we had a lot of experience developing web applications using Mac OS X, nobody at Kayak had ever worked on a Mac application, and there was a lot to learn: Objective C, Cocoa, and then the whole touch platform SDK. It was good to have some time to get up to speed, and to see what other developers did that was successful, or not.

I spent about three solid weeks getting deep into iPhone SDK and Xcode. It became really clear to me that I couldn’t do our App as a little side project. I had a my main job to do, which consists of many small projects, each of which needs tiny amounts of attention at any given time. About this time, we were lucky to find Christian, who had just returned from working in Rwanda on a free medical record system for developing countries called OpenMRS. He had never developed a Mac app, but was enthusiastic about learning the technology, and came up to speed very quickly.

While he was soaking up the wonders of Objective C, I sketched out what the app should look like and do. I like to use a CMM level 5 design process for new products. Well, no, not really. I just like to scribble messy pictures in pencil on scrap paper and then start coding. For the iPhone App, I wanted to be real classy, so I used paper with our logo on it.

As you can see, the launching screen was a really hard design problem. The key point of this screen is to tell the user, “Yes, you have launched the Kayak Application. Soon everything will be more awesome than you can believe.” Here’s the actual welcome screen:

The main search form on the home screen was quite a bit harder. I wanted to get something incredibly clean, obvious and nice looking. That combination is way beyond my capabilities as a product designer, so I scribbled “form TBD” and moved on. It turned out to be the hardest screen to get right, and we went through at least 5 or 6 complete redesigns. Luckily, Christian was very comfortable with scrapping lots of hard work and starting over. And over.

The most interesting things about this part of the design are the bottom tabs and the note “all pages are sticky between launches.” In regard to the latter, it’s a basic rule of iPhone apps that you’re going to get blown out of the water by a phone call or whatever, and you want to get the user back to whatever they were working on straight away. For the former, we knew from the start that we wanted icons, and generally like the ones we ended up with. But I’m no artist and I didn’t want to get hung up with that detail, so I just used FHBIR as the tab indicators. (I’m not telling you what “I” and “R” mean, those are top secret future functionality, and got dropped from the 1.0 for all the standard reasons that features get dropped from a 1.0 version: focus, resources, time, quality.)

Here is what we eventually came up with for the home screen. The form fields are patterned after fields that appear on in preferences. They just looked the cleanest, compared to a more webby label and text box style UI.

The flight results interaction was a lot more clear to us from the beginning. The navigation controller UI has been very clearly defined by Apple and pretty much every good app out there uses it in a very similar way. We wanted to stick to that model. We struggled the most with how to cram sorting and filtering onto the tiny screen. Here’s what I had sketched out at the very start:

As you can see, the sorting and filtering turned out quite a bit differently:

The notion of Cheap/Short/Soon as the main sorter, and pushing the stops, airlines and airports filters off to a secondary screen came from our notional use case: you are at the airport, and you need to get home or get to the next city right now. You probably have one of three things as you main constraint: money (obvious), time to get out of this airport (weather moving in), or time to get to your destination (to make a meeting or a soccer game.)

We talked about this use case so much, we came up with the airline phone number directory as a sort of bonus last minute feature. It’s kind of an oddity. I mean, you could enter all the airlines you are likely to fly in your address book. Or you could look them up in Google. However, keep pushing on that use case: you have no flight home, a storm is moving in, flights are being canceled, everybody in that airport is trying to get one of the remaining seats out of there. The airport wifi might require a credit card; EDGE or 3G coverage might be very weak or non-existent. You are standing there sweating, trying to beat everybody else to the reservations number for Jet Blue. If it’s baked into an iPhone app than can launch and dial in 10 seconds, you are going to be the winner.

Here’s the airline dialer:

If you have a friend with an iPhone, have a race. You put the Kayak app on your phone. Your friend should not have it. Have your friend name an airline. It should be one that neither she nor you know the number of. Start with your phones in your pocket. See who can get to an operator first.

Once we’d gone around about 15 times on the flight search UI, trying different forms and result techniques, we applied the methods that worked the best to the original hotel design:

which became:

Lincoln, our product manager, came up with the three sort criteria a desperate traveler might need: Cheap, Close and Classy.

Finally, we had the “Buzz” feature, which I had originally envisioned as looking a lot like the Stocks application that comes with the iPhone. “Buzz” is our feature that lets you see the best prices that other Kayak users find. It’s a good way to kill some time and contemplate possible vacations while you are waiting for the dentist.

Which came out as two screens instead of one. When you sketch on paper, you think you have more pixels than you actually have:

&nbps;

It just about exactly six months from the time we got officially accepted into the iPhone developer program to the day we got into the App Store. We’ve tried to anticipate user needs by thought experiment and usability testing. But we’ve done enough software that we know there will be some surprises and rude awakenings. We’re ready to change things around based on the integrated user feedback system. And we have a big laundry list of new features to implement.

I’m a man who loves a good book, and after a recent trip out east I realized there are so many destinations that honor their writers that it might be worth a ‘literary vacation’ at some point. My five favorites, and a quick note on each:

Boston
Thoreau’s Walden was written during his time living in a cabin on Walden Pond, just outside Boston. Nearby Salem is where Nathanial Hawthorne made his home, and Herman Melville wrote Moby Dick nearby.

London
Visit Westminster Abbey where authors like Chaucer, Dickens, and Tennyson have been laid to rest. The British Library holds original transcripts from such notable writers as Jane Austen and James Joyce.

Paris
Home to ‘The Lost Generation,’ this was where famed scribes like T.S. Eliot, Gertrude Stein, Ernest Hemingway, and Ezra Pound found writing styles that differentiated them from other Americans at the time.

New York City
Greenwich Village is famous for authors drinking heavily in the pubs, and you can even take a literary pub crawl! Visit Central Park’s Literary Walk to witness sculptures of famous writers throughout time.

San Francisco
The town owes quite a bit to literary pasts, and has streets named after authors like London, Twain, Bierce, and Kerouac. Many of them spent time in the city and surrounding pubs talking books and travel.

The All-Star game is about to begin, and being such a huge fan I thought it might be fun to write up my top five baseball towns.  Here we go, in no particular order:

5. New York
If you don’t know who the Yankees are, then you probably shouldn’t be reading this article. Both the Yankees and Mets are moving into their new stadiums next year, so don’t miss the chance to visit Yankee Stadium (for the history and nostalgia) or Shea (for the sound of airplanes flying overhead).

4. Chicago
Wrigley Field is one of the two most celebrated old time stadiums still standing, and a trip to Chicago isn’t complete without visiting this temple at 1060 Addison Street. The entire neighborhood is something to experience, from the stands on top of the apartment buildings overlooking the stadium to brews after the game at “the Cubby Bear.”

3. St. Louis
Have you ever seen a Cardinals game on television? The crowd is a sea of red, and they love their team. The Cards have moved into a new stadium, with a great location near the famed St. Louis Arch.

2. Boston
It’s difficult to find a town that loves their team more than the Fenway faithful. Home to Fenway Park’s famous green wall, the Red Sox games are a feat to behold. Go early for drinks at the Cask N Flagon, then grab a Fenway frank (a hot dog in white bread), and soak up the history of this 90+ year old institution.

1. San Francisco
You might wonder why I included this one – it’s because the Giants are my favorite team. Also, their ballpark is just a thing of beauty and ranked in the top of all stadium polls. Grab some garlic fries and sit in the upper deck to see great views of the Bay Bridge (and the entire bay for that matter).

Let me know what is your favorite baseball town and why!

5. Instead of Dallas… Austin
If you want to visit a Texas city, but would like to not sweat out your breakfast, Austin is the place to be – the weather is much more tepid than Dallas or Houston. It’s also considered the live music capital of the world and hosts many music festivals (and even more nightclubs and bars). The culture is hip and fun, and if you need proof, visit the Museum of Popular Culture in South Austin.

4. Instead of Phoenix… Albuquerque
See the Southwest at its most authentic as this New Mexico city. The Old Town offers colonial-style buildings, with Native American markets, museums, and more restaurants than you can shake a cactus at. Try everything from hot air ballooning, golfing, hiking, and other outdoor activities. Another little known fact – famous Route 66 rights right through the town!

3. Instead of Vegas… Reno
Sure, Sin City has the flash and notoriety, but if you break it down to basics Reno has everything you will need at a fraction of the cost. Famous acts like Larry the Cable Guy, Billy Idol, D.L. Hughley, Tom Jones, and Chicago. There’s of course, bowling (it’s the bowling capital of the world – don’t’ ask). Kayaking, skiing in winter at Tahoe, camping, golf, and of course gambling at any of the dozen or so resorts.

2. Instead of Boston… Providence
It’s only an hour or so drive down the road, but the New England feel is in full force. The downtown has been revived and offers an amazing open market, great shopping, and beautiful places for strolls, biking, or jogs. Nearby are Cape Cod, Newport, and quaint small towns with the rich history of our forefathers. Don’t miss the WaterFire, where 80 fires alight up the waterways while music plays in the background!

1. Instead of Washington, DC… Philadelphia
If you like history, The City of Brotherly Love has it. Ben Franklin practically built this place, and it gave birth to the American Revolution (not to mention it was the nation’s first capital). Some places to see is Independence Hall where the Declaration of Independence was first signed, the famous Liberty Bell, as well as many art museums that surround downtown. Compared to Washington, lodging and dining are very cheap. Remember to try a famous Philly Cheesesteak at either Gino’s or Pat’s – they are rival restaurants that both claim to be the first to offer the sandwich.

In order to save on fuel, some airlines are going through every idea in the book.  Many are retiring old planes that are less fuel efficient (compare an old Chevy van versus a new minivan).  Some airlines are actually flying their fleet a few miles per hour slower to a rate that is more gas economical.

However, the most interesting idea is to alleviate overall weight on a plane.  Ever see a movie or show where the plane was running out of gas, so the crew had to strip it of everything heavy?  Apparently the airlines have seen the light and are using similar tactics.  Some ideas are putting less water on planes for bathrooms, removing paint, taking off old drink carts for lighter ones, reducing the number of magazines and newspapers, and even washing planes daily (that dirt and grime only helps slow planes down), or even removing the exterior paint.

Any other ideas to get better mileage?