Updated pricing and additional components.
CPU: Intel Core 2 Quad Q6600 ($290) - TigerDirect.com
Motherboard: GigaByte GA-P35-DQ6 $229 - Newegg.com
Cooling: Thermalright Ultra 120 Extreme $55 - Quietpcusa.com
CPU Paste: Arctic Ceramique $5 - Newegg.com
Video Card: AMD HD 2400 Pro $50 (damn you Mize!) - Newegg.com
Hard Drives: Hitachi T7K500 (3x500GB) $330 - TigerDirect.com
Case: Cooler Master Stacker 832 $210 - Computerbrain.com
Monitor: BenQ FP241WZ $770 - TigerDirect.com
Power Supply: Silverstone ST85F $180 + $20 mail-in rebate - Newegg.com
CD/DVD Burner: Lite-On LH-20A1L-06 $40 - Newegg.com
Case Fans: Scythe S-FLEX SFF21E (1200rpm, 49cfm, 20 dBa) (x5) $72 - Coolerguys.com
Keyboard + Mouse: Microsoft Intellimouse Explorer 4.0 + Natural Keyboard Elite (already owned)
OS: Windows XP SP2 (already owned)
Memory Candidates: 2GB DDR2-800 (2x1GB only) - 32bit Windows XP can only address 4GB, of which some will be wiped away for hardware requirements. That will leave anywhere from 3GB-3.5GB of usable physical memory, which would basically be a waste of money by getting 4GB.
Patriot 2x1GB DDR2-800 $119 + $45 mail-in rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220144
Corsair 2x1GB DDR2-800 $120 + $40 mail-in rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034
Any others? I'm heading home now. Will put through the orders tonight. Cya in an hour or so.