In English, this should work fine most of the time. Also consider just using sounds (like different beeps) for all the actions you can. Voice feedback is slow, so I only recommend to use it for output of names etc.The voice feedback is easy -- I'm just not sure if I'll be able to get it to say things like the current artist and song info.
Contour design shuttles (express, pro) work fine with Mac, the same is true about Logitech NuLOOQ (which is much better built mechanically than PowerMate). Both have plenty of programmable buttons to implement what you want.I think the powermate should be able to provide volume control and possibly song control (pausing/playing/next/previous). In the input devices forum, I saw some very interesting alternatives to the Griffin Powermate -- the only thing is, I'm not sure if those can be made to work as easily with a PPC Mac.
Not exactly, but both my apps (TatraApp and shortly QCar) have the voice feedback capability which allows limited use without screen. But the whole thing is a pain in the butt (setting proper timeouts so the software does not start to speak too soon or too late etc.)I haven't been able to find any other headless mac mini projects. Has anything like this ever been tried before?