Corsair XMS2 4GB (2 x 2GB) PC2-8500 DDR2 Desktop Memory Kit for $34.00 shipped after this $30 rebate. Here is a screenshot for your reference. For the technically inclined, this set of RAM has a voltage specification of 2.1v and operates at 1066 MHz with 5-5-5-15 timing. As a comparison, Amazon sells it for over $45 after the same $30 rebate.