clean desktop (mac)

a little bit off topic: some time ago, i´ve read - and i think it was on an antville site - that there is a programm, that resets your mac desktop to the standard look for a desired time (preset background, only pre-installed programms, no files to lie about...). apparently, this tool is very usefull for presentations. so, does anyone know about it? any links?

cheers, v