Memory Master 4 GB (2 x 2GB) DDR2 800 MHz PC2-6400 Desktop DIMM Memory Modules MMD4096KD2-800 at Amazon.com
CMS 4GB (2X2GB) DDR2 3200 400MHZ ECC Registered DIMM Memory Ram Upgrade Compatible with Dell® Poweredge 2800 Ddr2 Single Rank for Server Only - B66 at Amazon.com
Micron 4GB PC2-6400P DDR2 Reg ECC MT36HTF51272PZ-80EH1 at Amazon.com
DDR2-4GB-PC5300-ECC-REG at Amazon.com
EMMCRAM 8GB (2 x 4GB) PC2-6400 DDR2-800 200PIN SoDIMM Laptop RAM Non-ECC Unbuffered Notebook Memory for Dell E6400,E6500, Inspiron 1545, M4400,E5500 at Amazon.com