UPDATE: using Kubuntu 12.04.1 LTS.
Community supported until April 2015. So far so good.
Messing with my PowerBook, in 2 days, i managed how to get sound and Airport Extreme to work. Later i got the PMU (power management) working.
I self-compiled and tested Linux 3.6.0-rc4 kernel (not-ubuntu) and the PMU stopped working. After that i run apt-get upgrade and got an update to the 3.2 kernel, which was somewhat better and stable.
I'm thinking to write a guide...