Farecast

Farecast.com is a price prediction site, which helps you find cheap airfare and cheap hotel stays. It was founded by Oren Etzioni, Director of the Turing Center and Computer Science & Engineering Professor at University of Washington.

The way it works is you punch in dates and locations for a flight you'd like to take or a hotel you'd like to book, and Farecast will tell you if you should buy now or wait. Their recommendation is based on whether the price is predicted to go up, down, or stay the same. Farecast compares the current rate to observed historical rates. Farecast was formerly known as Hamlet ("to buy or not to buy...that is the question"), but they (luckily?) changed their name.

There's a lot of computer nerdiness that goes into predicting all this, and the website wisely does not go into too much detail, likely in order to protect its pending patents. I'm sure it involves lots of mathy vectors and learning algorithms though. I would elaborate on these conjectures, but I slept through that Neural Networks class. I knew it wasn't a good sign when the first thing I saw when I walked in were incomprehensible symbols scrawled all over blackboard ("Guys, guys! Why are the triangles upside-down? What's a gradient?). Sigh. I digress.

The beta site launched in May of 2006, and the bona fide site launched a year later. In August 2007 the hotel tab was created, and in February 2007 the Fare Guard launched. The Fare Guard allows users to lock-in a specific price for a flight and be protected from future price increases for the following seven days. Most recently, in April of 2008, Farecast was bought by Microsoft at an estimated value of $75 million – $115 million. Cha-ching!

I like the "compare search" feature that checks Farecast's prices against Hotwire, Priceline, Orbitz, etc. without having to re-punch in the data. The site is a little cluttered. It's not horrendous, you can tell some poor designer tried really hard to talk the content people into displaying less. But the site is still bloated with information. It would fit right in with the Bloomberg channel or the Stock Exchange floor. Such is to be expected from finance and computer people; they don't feel safe until they are buried under a mountain of numbers and graphs. I'll grant you that the few graphics are well-drawn and friendly. And I love me some cheap deals, so overall grade: solid A!

Runner up:
Perfect Pitch, the game. It's got a couple of glitches and horrendous fonts, but overall it's fun. Also, it's only testing "perfect pitch" for the first note. After that it's relative pitch. Unless you're a goldfish. They get plus points for the sparsity. The way it works is you hear a tone, and try to find the corresponding note on the virtual piano. I wasted minutes on this thing. MINUTES! Anyway, there's also that musical intervals trainer if that's your kind of thang.

(From Wikipedia, Oren Etzioni's site, and Mefi)