I will need to set up, with a very short lead time, around 20 PCs for use in a weekend-long tradeshow environment. These are just for doing mail, IRC, and IM. The boxes are Shuttles and come with no OS and no OS license.

I'm thinking the best approach here is to just stick one of the Linux Live CDs in each drive and let them go. Hopefully I won't have to do any configuring and custom ISO building. Really I just need something that will boot into an OS, get an IP address from DHCP, and provide easy access to a browser, Gaim, and an IRC client.

Anyone have experience with various "ready to run" Live CDs? Which one would be the best for what I need to do? Or is there another way (Windows is not an option and I'm not interested in Mac minis either, thanks).