4GB DDR2-533 RAM Memory Upgrade for The IBM ThinkPad R60 Series R61 (8934F9U) (Genuine A-Tech Brand) at Amazon.com
Lenovo ThinkPad R61 15" Laptop Intel Core 2 Duo 4GB RAM 80GB HDD Windows 7 | eBay
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