2GB Memory RAM Upgrade for the Lenovo Thinkpad R61 Series T60 Series T61 Series X60 Series and X61 Series Laptops (DDR2-667 PC2-5300 SODIMM) - Walmart.com
CMS 8GB (2X4GB) DDR2 5300 667MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with IBM Lenovo® Thinkpad T61, T61P Ddr2 Pc5300 Sodimm - B116 at Amazon.com
8GB 2X4GB Compatible Memory for Lenovo Thinkpad T61 T61p DDR2 PC2-5300 SODIMM RAM (PARTS-QUICK Brand) at Amazon.com
IBM Thinkpad T61 RAM Replacement - iFixit Repair Guide