I like to play with different Linux distro's, but I don't have a lot of extra hardware lying around to put them on. So I've played with a lot of the different LiveCD's out there on my laptop and several other systems. It gives me a chance to learn what they're capable of. Each LiveCD distro has different tools and hardware recognition capabilities, so you sometimes have to switch distro's depending on what you're trying to accomplish.
Now, according to Linux.com, there's a script that will allow you to boot to a number of different distros from the same DVD
. This is especially nice if you're using the LiveDVD for forensics work or to experiment with cracking wireless encryption (with permission, of course) The script works with over a dozen different distributions of Linux, though you won't be able to fit all of them on one DVD. Have fun.