HP Touchpad running Ubuntu Linux!
We managed to get our hands on an HP touchpad in the fire sale, and I've been playing with getting Linux running on it. Here are a couple of videos of where it's at so far. About the only thing not working at this point is screen rotation, which I personally don't have the skills to implement. Hopefully the webos-internals crew will get it figured out soon.
A couple of key tools making it workable on the tablet are easyswipe for gestures and onboard for the onscreen keyboard. I had to build my own onboard keymap for the device. The desktop environment is LXDE, to keep things light and snappy.
For instructions on how to do this, check out this thread at precentral. The first post will get you into a basic Ubuntu environment, then my instructions on how to get to a nice desktop are down on page five of the thread.