Crucial 2GB Single DDR2 667MHz (PC2-5300) CL5 SODIMM 200-Pin Notebook Memory Module CT25664AC667 at Amazon.com
Amazon.com: OWC 2GB (2 x 1GB) PC5300 DDR2 667MHz SO-DIMMs Memory Compatible with MacBook/MacBook Pro, iMac, and Mac Mini Models (OWC5300DDR2S2GP) : Everything Else