Corsair XMS2 4GB (2 x 2GB) PC6400 DDR2 Memory for $9.99 after a $25 rebate. Shipping is $4.99 so the total comes to $14.98 shipped. For the technically inclined, this set of RAM has a voltage specification of 1.9v and operates at 800MHz with 5-5-5-18 timing. More information is available here.
This deal has expired. Congratulations to those who were able to get in on it.