http://aws-musings.com/4-easy-steps-to-enable-remote-desktop-on-your-ubuntu-ec2-instance/?utm_source=HackerNews&utm_medium=web&utm_campaign=nx

Enabling remote desktop on an ubuntu ec2 instance is pretty easy by using NX. We will use FreeNX at the server and NoMachine NX client on the client machine. NX is a much better alternative to VNC. You can install NoMachine client on windows, mac or linux.