Not to piggy back off your question but...

I am also looking for cloud based hosting for a demo environment. I know Microsoft, Google, Amazon, etc are all in a pricing war right now and cutting prices, however, I have not been able to find a comparison of these companies online. Which his better, cheaper, most flexible, etc. Are there other good hosts out there.

Basically I want to be able to get VMs ready for demo at a user group (So they may be online a day or two a month).