I figured this would work from the first post. There was already a VERY long post, later turned into a front page article here, about a guy running an 8800GTX on a 280 watt high efficiency power supply.
I've been running the setup in my sig since May with the 8800GTS and with my older video card for almost two years. I only get problems trying to overclock my video card once the CPU is at 3.74ghz or higher. But even 3.70 and clocking my GTS up to 640core 1100 memory my little bluestorm is able to get the job done.
I would imagine I wouldn't have too much trouble running a GTX.
I can't imagine what these people using 750 and 1000 watt PSUs are trying to run...