cudatest (specifications list from Martin Merck)

1 x ASUS P6T Motherboard
12 GB Ram
1 x Intel i7 920 (2.66 GHz)
1 x NZXT Tempest case
1.5 TB Hard Drive
1 x OEM Samsung SH-S223B/BEBE DVDRW Drive
1 x Microsoft Business Hardware Pack Keyboard and Mouse Combo
1 x Acer H233Hbmid 23" Widescreen HD LCD Monitor
1 x EVGA GeForce GTX295 CoOp Edition
2 x EVGA GeForce GTX295 Superclocked Edition
1 x Corsair CMPSU-1000HX 1000W ATX12V 2.2 power supply
1 x FSP Group Booster X5 450W supplementary power supply

3 GTX295 (=6 GPUs and a total of 1440 cores).
NVidia claims a total of 5.36 Teraflops.

In total we have spent $3215.48 for the system including monitor
and a first power supply which we had to replace later.

Update (3/5/10): all 3 GTX295 cards are now Superclocked Edition