Useful air travel sites

I thought I'd post some of my favorite auxiliary travel sites:

Flight Stats is an amazing tool. It tracks flights (within the US and Canada, plus I think selected international flights), gives information on airport delays, and even lists scheduled flights up to three days in advance. This last is useful for figuring out beforehand how much congestion you'll face upon arrival.

Seat Guru is concerned mainly with information about seats on different airlines, sorted by plane type, but it also has info on other aspects of the flight. Things like meal and drink service, power outlets, entertainment options, aircraft maps, etc.

Aside from these sites, you can always check the website for the airports you're traveling from and to. These vary a lot in quality (Mexico City's is pretty good) and utility.