OWC 8GB PC8500 DDR3 ECC-R 1066MHz DIMM Memory Compatible with Mac Pro & Xserve 'Nehalem' & 'Westmere' Models (OWC8566D3MPE8GB) at Amazon.com
OWC 4.0GB Mac Pro Early 2009 Memory Matched Set (2x... at MacSales.com
OWC 8GB DDR3 1066 MHz SO-DIMM Memory Module (Mac)
8GB 2X4GB Memory RAM for Apple Mac Pro MD771LL/A 240pin PC3-8500 1066MHz DDR3 ECC UDIMM Black Diamond Memory Module Upgrade - Walmart.com
Amazon.com: OWC 16GB (2 x 8GB) PC8500 DDR3 ECC-R 1066MHz DIMMs Memory Compatible with Mac Pro Early 2009 & Late 2010 'Nehalem' & 'Westmere' Systems and Early 2009 Xserve. (OWC85MP3S8M16GK) : Everything Else