I have been playing on and off with Amazon EC2 for some time now, having been lucky enough in the first place to get an account. I originally had an Amazon AWS account for S3, the storage part of the service. Hence the lucky bit -- getting an invite for EC2 -- the elastic compute cloud.
For me it has been a highly educational experience, coming from a Windows background. It gives me a remote linux workstation to play around on with plenty of storage and bandwidth available.
Install Apache? No probs.
Install MySQL? No probs.
OpenOffice? Easy.
All in all an interesting experience. Not free though, you pay by the hour and it can add up over time.
Well worth checking out.
I am planning a blog post showing how to get Ubuntu up and running and then connecting to the server using VNC. I've done it a few times and I know it would be of interest to a lot of people.
As ever... Stay tuned.
Update:
Here's a very cool link on this topic.