Hey, I've been looking to do the same thing, however it seems as though we will both run into significant problems. Mainly that, to the best of my knowledge 'Canonical' (The makers of Ubuntu) don't officially support ARMv7 (the processor that Raspberry Pi uses). Unofficially, there are apparently ways to do this, but I think they involve using multiple Raspberry Pi's in conjunction to manually build a personalised package (hassle much?).
Personally I still want to switch OS's as I find the Raspbian OS awkward and unnatural as far as a Linux distro goes. So the options seem to be:
- Download one of the other OS's that officially support the Raspberry Pi.
from here http://www.raspberrypi.org/downloads
I think I'll give RISC OS a try.
- Try Debian or similar.
I'm relatively sure that there are other various mainstream Linux distro's that do
officially support the Raspberry Pi, however they will have to be lightweight enough
to run without almost melting it.