Cheap Flight Sites

Ultimate Fares: http://www.ultimatefares.com/

Cheap Flights: http://www.cheapflights.com/

Booking Buddy: http://www.bookingbuddy.com/

Kayak: www.kayak.com

Farecast: http://farecast.live.com/


FlightStats: http://www.flightstats.com/
You can track your flights using flightstats.com—not just immediately before you take your flight, but before you even make your reservation. FlightStats offers a great historical picture of the yearly on-time performance of every scheduled flight. Obviously, a flight that is late 96 percent of the time—and unfortunately there are a lot of them—is one you don't want to book in the first place.

FareCompare: http://www.farecompare.com/
FareCompare is a great website that analyzes airfares (and changes in those fares).