and is it possible to play full screen on a powerbook?
Fuckin' hell are the image stretching options lame. 1x, 2x, 3x, etc.. no fit to screen options (if you go 1x and stretch to fill screen, you'll get a normal resolution screen in the middle of a whole shit load of black). Maybe if that were ever fixed then I'd play with MacMAME more, though the CPU requirements are insane.
Macs suck for emulation :(