Me, I'll stick with my AlBook (it's a purchase you won't regret), as I need the extra CPU cycles, better video card, and desktop res, but my girlfriend's iBook G4/12" is still a great machine, and for the price difference, I can understand why the iBook may be the more sensible purchase. Certainly, lots of iBook owners running LinuxPPC at Linux.Conf.Au; surprising amount of PPC users, actually.
salmoni: Email me - UI design with mgw is something our company's been working with for almost a year now, and I've been wanting to give back to the open source community for ages now, but headache galore timewise. I'd really like to bash brains together on this one.