You might also have a look at Yellow Dog Linux (YDL). Here you find a list of supported hardware. It worked very well for me on a Titanium PB. The installation was almost painless, just had to address an issue with the graphics driver software. In case you start to fiddle with such installation, probably with dual or triple boot bootloaders etc., do most carefully read and follow the instructions. However, back up your harddisk before installing stuff like this. There are chances to mess up your system completely.