I think some of us are counting on the price to rise before we see significant return on investment. And for some others, electricity may be free, or at least n

I think some of us are counting on the price to rise before we see significant return on investment. And for some others, electricity may be free, or at least not paid by themselves. As for estimating the whole network's energy, here's a gross, probably exaggerated way to measure it. My 5870 gets 370 Mhash/s at 188 W. The current network rate is 2000 Ghash/s. 2000 / 0.37 * 188 = ~1 megawatt. Seems reasonable, especially since it's distributed worldwide.