From an e-mail we received.

Buy a Chipotle Gift Card of $10 or more for your Valentine February 1st through February 12, 2008. Bring back the gift card receipt on the 13th or 14th for a Free Burrito. Must purchase the GC from a restaurant and not online.

DS already bought a GC tonight and is looking forward to his Valentine's Day Burrito! Chipotle always honors the purchase of tacos if you don't want the burrito.

Thanks OP! I love Chipotle!