OWC 8 GB (2 X 4GB) ram PC8500 DDR3 1066MHz sodimm 204-pin Memory Upgrade Kit, (OWC8566DDR3S8GP), Compatible with MacBook Pro, MacBook, Mac Mini and iMac at Amazon.com
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
8GB kit (2x4GB) DDR3 1066 SODIMM for Apple iMac (2009), MacBook Pro (2 – Aplus Technology
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
Timetec Hynix IC 16GB KIT(2x8GB) Compatible for Apple DDR3 PC3-8500 1067MHz/1066MHz Upgrade for MacBook 13'' Mid 2010, MacBook Pro 13'' Mid 2010, iMac 27''Late 2009, Mac Mini Mid 2010(16GB KIT(2x8GB)) Laptop Memory -