I've been looking for a way to play around with linux without having to commit a whole comp to the cause.
This is the way. It's called Knoppix, and it's Linux with full-blown GUI environment (using KDE), and it runs all from 1 cd. Tons of apps, you don't need to commit anything on your comp to it.
Another use for this can be if your Windows takes a crap, you can pop this in, set up FTP and recover some files.
JUST REMEMBER:
NEVER write to an NTFS partition using this, bad things will happen.