Renting stuff off the Cloud

While chatting with the owner of BuUuk.com(Jon), he briefly mentioned that he was using Amazon EC to serve static content at a cheap rate. This got me thinking - perhaps I can host my lab machine on the cloud and rent it at a far cheaper rate than what I would pay for a physical machine. I'll have to do my calculations( or best impression of it ) and then dive in and hope for the best :)