CNC Torch Table LinuxCNC
Update: LinuxCNC is available for Ubuntu 10.04LTS 
We are as of Sept. 4, 2009 using an IBM ThinkPad laptop graciously donated to the cause by Inga. It has the latest EMC2 installed from the Ubuntu 8.04&EMC2 Live CD.
If you're starting from a pre-existing Linux install, like I was, then read this important user contributed wiki. I had to reinstall using the 8.4 live cd because 8.10 of Ubuntu wasn't supported.
Once you get that all installed, the best documentation available is from the user contributed wiki and the included manuals. For example, when I had trouble with getting the IBM laptop to talk to the motor controller, I used [this walk-through] to step me through a working install which lead me to the actual problem of the IBM laptop having a non-standard printer port address.
Once I got the stepper motors twitching to my every whim, I put it all down and will continue from where I left off once I get the little beasties mounted.
A quick note: this link is Very Important. It discusses how to install and use a kernel module that disables power saving features which improved our performance by an order of magnitude. Of special note, "For Hardy you don't need to compile or install it, it's already there (go to step 6)." which is what we are using because we installed off the emc2 live cd :-)