Delaycast is a website that predicts airline flight delays at 60 US airports, and reports on ten major airlines.

Wired news had a story last week about the new service, and said that the predictions of which flights will be delayed came within 15 minutes of what actually happened.
A next step they are considering is to provide data about how long the security checkpoint waits will be.

“Delaycast gathers historical delay data and runs it through powerful computers, using algorithms to search for patterns. This gives it a road map it can use to anticipate future delays. It’s predictive modeling, and its similar to what sites like Farecast use to guess which way ticket prices are going to go.

Right now Delaycast provides two different tools, and they’re both pretty cool. Delay Profiles predicts delays for a single airport, either by time of day, day of the week or airline — 100 on the index equals the average, so a score of 120 means that delays are 20% above average.
http://blog.wired.com/cars/2008/04/using-predictiv.html