Mt Gox (http://mtgox.com/ http://mtgox.com/) and others let you trade Bitcoins for USD and vice versa. I don't know how much computational power you need to gen

Mt Gox (http://mtgox.com/ http://mtgox.com/) and others let you trade Bitcoins for USD and vice versa. I don't know how much computational power you need to generate a Bitcoin, but the current exchange rate seems to be 1 Bitcoin = 0.280 USD. The few other exchanges I checked out having similar exchange rates.