There's also portable apps for Mac OS X, although I haven't tried it: http://www.freesmug.org/portableapps/ Since we were talking about portable classroom not
... Looks pretty cool. http://portableapps.com We could sell USB keys w/this stuff installed on them. I'll check it out this week -- remind me at the CWE Lug
And extending it further, use Portable Apps. No installation necessary. Run it from a CD. Or if you want, drag the whole PortableApps folder from the CD to