JetBlue is offering $30 off certain routes for travel between Oct 23 and Dec 15, except, you guessed it, peak Thanksgiving travel (Nov 21- Dec 2). Use promo code JetOct08 on this page.
The eligible routes are listed below in airline code.
Terms and Conditions:
*Offer ends October 16, 2008 at 11:59 PM MT. Promotion/Discount Codes may not be combined and is not valid for travel outside the continental United States, on intra-California routes, or on any of the following routes in either direction:
Code is valid for $30 off of r/t travel that is purchased by October 16, 2008, 11:59 PM MT, for travel between October 23, 2008 and December 15, 2008. Blackout dates are between November 21, 2008 and December 2, 2008. Discount will be deducted off of base fare. If Discount Code travel is changed outside of this window or cancelled, discount will be forfeited and you will be responsible for the fare difference plus $100 change/cancel fee per person. Cancellations are for a JetBlue travel credit only, which is valid for one year. If a reservation is not changed or canceled prior to scheduled departure, all money associated with the reservation is forfeited. Discount may be used only toward newly-booked travel and may not be applied to existing travel or changes to travel. Discount may not be redeemed for cash. Discount may be used only for flight purchase made via jetblue.com. Discount codes are transferable. Discount may not be used in conjunction with other special offers or towards the purchase of a JetBlue Gift Card, Getaways vacation packages, JetBlue Cruise or already booked flights. All fares must be purchased at time of reservation, and are one-way, and nontransferable.