I've downloaded the Amazon Ubuntu EC2 AMI images (from http://uec-images.ubuntu.com/releases/10.04/release/) and I am trying to run it locally on my linux desktop. Is it possible to run the AMI using VirtualBox? Is some other virtualization software required?
Link provided Istvan is down.
Amazon now provides tool to export your EC2 image as Virtual Machine image ready to run locally:
PS Please note that this method only works for Windows VMs