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) at Amazon.com
Refurbished Lenovo ThinkPad R61 Laptop Core 2 Duo 2 Gb Ram 160Gb HDD Windows 7
Tutorial: How to upgrade ram in a T61 Thinkpad - YouTube
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
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) at Amazon.com