There are plenty of pricing cheat sheets out there, but we couldn't find a tool that would let us compare cloud providers while taking one-year or three-year EC2 reservations into account, or answer questions like "who has the best price per GB of RAM", so we built this. We'd love feedback -- what can we do to make this more useful?
For more discussion and some interesting results, check out http://blog.scalyr.com/2013/11/11/cloud-cost-calculator/.