Great NYTimes travel article about dealing with delayed or canceled flights.
How to Fight Back When Your Flight is Canceled
I've been fortunate to have flexible days when traveling from NYC --> CAE, but Carla has gotten trapped or significantly delayed several times--this is one of the reason we don't fly together
I've never had the chance to be bumped, but according to the Department of Transportation you are entitled to $400 if you are bumped and placed on a flight within the next two hours and $800 if you are bumped and placed on a flight rerouted outside of that two hour window. This would be a clever game to play if you know you have some flex time. Make sure you are the last to check-in and then wait and see if you get bumped. . . though you might have to convince people not to take the lesser amount that is offered to volunteers.
The article also says should print you're "contract of carriage" and take it to the airport with you, or you could just bookmark my blog.
We tend to fly US Airways, and here is their contract of carriage, which says the $400 dollar maximum compensations:
This compensation is in addition to the value of the passenger’s ticket which he or she can use for alternate transportation or have refunded if not used.
Here are some major US airline's(some of these are pdfs)
Jetblue's Contract of Carriage
Southwest Airlines Contract of Carriage
Delta's Contract of Carriage
United Airlines Contract of Carriage
Continental Airlines Contract of Carriage
American Airlines Contract of Carriage