Try Windows Azure

A credit card is required to sign up for the trial. The trial includes monthly allocations for use. If you exceed these allocations, a spending limit will apply and your service will be disabled until the beginning of the next billing month; you will be required to redeploy your application and your subscription will expire at the end of the trial. If you remove the spending limit, any usage in excess of the monthly allocation will be charged at standard rates. At the end of the trial, any further usage will be charged at the standard rates. Once the spending limit has been disabled, it cannot be enabled again.