I suppose it could work on an aluminum. The bezel width is not an issue because aluminum is far stronger than plastics, which is why the MBP could fit one in the same width; however, the issue with the bezel is where the clasp is. The MBP has two clasps, with the camera seated between the two. The Powerbook G4 has one, seated right in the middle of the top, where the camera would be. I do not think you could put a camera there without compromising the strength of the bezel. I guess you could put it to the left or right side, but that'd look a tad ugly, no?