I'm pretty sure my power supply can handle two 260 GTX's, but thought I'd run it past some of you who have already run 8800GTX's in SLI and may know. I'm running a 700 Watt OCZ GameXStream Power Supply
(see link for Amp/Rail info) with three HD's, DVD Burner and only one expansion card other than my Graphics card (audio). I don't think I'm pulling down that many watts, and I think I have enough 12v rails that I should be able to give each card enough of their own that there shouldn't be much trouble... although since the PSU comes with two 6-pins, maybe I should split that rail and another 12v rail with the adapters? Any comments/experience welcome.