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
CMS 8GB (2X4GB) DDR2 6400 800MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with IBM Lenovo® Thinkpad X61 Notebook Ddr2 Pc6400 Sodimm - A41 at Amazon.com
Finally replaced the fan, battery, and wifi in my X61. Only other area of upgrade would be getting an LED kit for the screen. : r/thinkpad