If you are even remotely considering cloud computing, you owe it to yourself to begin with the Ubuntu Enterprise Cloud (UEC) open source cloud software. More here
There are many reasons for this. Not only is this tool feature-rich, it is also free. If you are only just now trying to decide if you want to deploy a cloud environment, then you do not want to shell out your entire IT budget only to find out if cloud computing is for you (or your company). That is where UEC comes in.