Mailing the story:

This tutorial provides step-by-step instructions on how to install images of Xen on an Ubuntu Hardy Heron (Ubuntu 8.04) server system (i386). Linux distributions that can run as Xen guests out of the box, obviating the need to create your own custom filesystems. The filesystems on jailtime.org have already been tweaked to deal with Xen’s idiosyncracies, and are also designed to be lightweight and minimally divergent from the original distribution.