Can the Late 2009 27" iMac handle 32GB of RAM? | MacRumors Forums
Install memory in an iMac - Apple Support
Memory Upgrades for Apple iMac 2011 Up to 32GB
4B (1X4GB) RAM Memory for Apple iMac "Core 2 Duo" 3.06 21.5-Inch (Late 2009) A34 | eBay
Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC3-8500 RAM for Mac Book (Mid 2010 13-inch), Mac Book Pro (Mid 2010 13-inch), iMac (Late 2009 27-inch), Mac Mini (Mid 2010)
8GB -2x4GB Memory Ram Upgrade 20" Apple iMac 9.1 2.66GHz Core 2 Duo Early 2009 | eBay
A-Tech 8GB (2 x 4GB) PC3-8500 DDR3 1066/1067 MHz RAM for MacBook, MacBook Pro, iMac, Mac Mini (Late 2008, Early/Mid/Late 2009, Mid 2010) | 204-Pin SODIMM Memory Kit