EC2

Elastic Compute Cloud, video tutorial.
Create a machine image (AMI) and upload it.
- They provide basic images (Fedora) which you can then modify and save.
- See vmware and other virtualization vendors.
RAM: 1.7GB–15GB, CPU(1Ghz 2007 Opteron/Xeon): 1–4 core, HD: 160GB–1690GB. All virtual!
Pricing: $0.10/hour to $0.80/hour. Pay only when they are running.
Can run as many instances as you can pay for. Spawn new ones in a minute.