Might try MorphOS - Ok HW?

[pVC]

I guess it's this model http://www.everymac.com/systems/apple/powerbook_g4/specs/powerbook_g4_1.0_15.html

It's a lower end aluminum PowerBook with quite low resolution (1280x854), but still a little better than in iBooks for example. 64MB graphics memory, which is fine for that resolution, and again more than in iBooks, although less than in the best Powerbooks.

Multi finger gestures on the touchpad are only supported on higher end Powerbooks, but otherwise I think it would be a fine machine for MorphOS. Especially for the price which isn't much. I'd avoid titanium Powerbooks, but I guess any of these aluminum Powerbooks are quite fine.