JetBlue and American Express team up periodically to provide special deals for JetBlue flights booked with an Amex card. This latest deal is unique in that not only do you get a $25 discount on any roundtrip flight, but you also receive a $25 American Express gift card (which is as good as cash).
This offer is valid anywhere JetBlue files for travel between Nov 17 and Dec 18, 2007. You must book by Nov 17 through the following link on JetBlue's website. Additional details and restrictions can be found there.