I'd like to volunteer to work on a PPC port of Haiku.

My programming skills are a little rusty (I took 2 years of C++ 5 years ago). But, I'd be willing to give it a shot. I may not be able to write anything advanced, but I've got time and patience to help build PPC binaries.

I use a 12" Powerbook G4 that I can't bring myself to replace...

I used BeOS R5 on a desktop before I switched back to Mac. I loved it, but I jumped ship when the company folded.