A very sweet bit of mac software I just ran across, thanks to the acute eye of my little bro David. Go find it here: http://wsmanager.sourceforge.net/.
Apparently, you can run a UML slice on a host with a different kernel version. I didn't know this. But you should run in Skas mode, if possible. And the skas patch hasn't really worked for me on the latest kernels (2.4.24). Doh-well.