This one might be better filed in the category of ... Don't try this at home.The guys from XDA-Devs have Ubuntu, the Linux distro, running on the Samsung Galaxy Tab. As with most of these unsupported ports there are a lot of "gotchas" and it's more about seeing if you can make it work than trying to use it.
Since the OS is not designed for touch devices it won't be real useful without a mouse and keyboard :) If you're a geek and are interested in powering the Galaxy Tab with Ubuntu you just might enjoy following the long step by step installation procedure. :)
Here's a video to see it in action. The Tab is a pretty great interface already, but this is cool!