Hynix 4GB 2 x 2GB PC2-6400U DDR2 800 MHz Non-ECC Unbuffered Desktop Memory Kit at Amazon.com
TECMIYO DDR2 PC2-6400 DDR2 800 4GB Kit (2x2GB) Non ECC Unbuffered 1.8V CL6 200-Pin Sodimm Laptop Memory Module at Amazon.com
Amazon.com: High Performance Memory Module for RAM for Intel/AMD (2GB, DDR2, 800MHz, 200PIN, PC-6400), Compatible with Your Digital Smart Computer/Computer : Electronics