Steve,
I read on the CUE Ning that you had set up there an LTSP network with Ubuntu. I tried running Ubuntu on my desktop, and got it to work for a while. I tried setting up two other old computer to boot as thin cleints, but couldn't get it to work. I blogged my Edubuntu experiment on my What is School 2.0? blog. After several reinstalls, Edubuntu failed to successfully install at all. I'm now running OpenSUSE, but I did like Edubuntu. I need to be able to troubleshoot the network setup to see why the thin client weren't connecting.
There's a link to a writeup on setting a little demonstration/experimentation Edubuntu thin client network using a MacBook (for the server), VMWare Fusion, and a Dell laptop as the thin client.