Between September 8 and October 8, fly an unlimited number of times with JetBlue's new All-You-Can-Jet Pass. For $599 including most taxes and fees, hop any of JetBlue's routes from 57 cities and more than 600 daily flights for an unlimited number of times for one month. By purchasing a pass, you will earn thirty-five (35) TrueBlue points good toward future travel, too.
Book by August 21, 2009. If the offer is too popular, JetBlue may stop taking orders, so act as soon as you can.
For more info, see jetblue.com. Passes can only be booked via 1-800-538-2583, though the airline will waive its customary $15 phone booking fee.
THE FINE PRINT
Non-refundable, non-transferable, and non-auctionable. If you book a flight and then don't show up, you'l be hit with a $100 fee, though you have up to three days prior to a flight to cancel. Travel to or from an international destination city or Puerto Rico will incur government taxes and airport fees. Other restrictions apply (PDF).
UPDATE 8/20: This offer is now sold out.