4GB [2x2GB] DDR2-667 (PC2-5300) RAM Memory Upgrade Kit for The Apple iMac 7,1 (20-inch, 2.0GHz, MA876LL/A) Intel Core 2 Duo (Genuine A-Tech Brand) at Amazon.com
Kingston 2 GB DDR2 SDRAM Memory Module 2 GB (1 x 2 GB) 667MHz DDR2 SDRAM 200pin KTT667D2/2G at Amazon.com
Kingston 2 GB DDR2 SDRAM Memory Module 2 GB (1 x 2 GB) 800MHz DDR2800/PC26400 DDR2 SDRAM KTD-INSP6000C/2G at Amazon.com