^Yup, it definately pays to check. The interesting thing is that the discount carriers such as AirTran, JetBlue, and Southwest limit you to 3 70 pound bags, while the more expensive carriers like United, USAir, Delta, and American usually limit you to 2 50 pound bags.
There is a table of various airline limits at
http://www.thetravelinsider.info/tra...allowances.htm