I enjoyed Shawn's presentation tonight. For those who would like to try out a Linux Jails equivalent see http://openvz.org/
Unlike FreeBSD the OpenVZ kernel mods have not made it into the mainstream Linux kernel. You have to get a kernel from the OpenVZ site.
It is certainly not as easy to configure as Jails but there are templates available for various Linux distros to make the job easier.
-- Bill