Classic Mac alternative input devices
I have wasted much time researching this topic, to no avail, so I finally decided to ask some people who might actually know: you guys!
I'd like to see a list and discussion of alternative input devices for the classic Mac, particularly pre-ADB, but ADB stuff is interesting also. I am especially interested in knowing if there were ever any light pens compatible with the early Macs. All other suggestions, such as tablets, trackballs, one-handed keyboards, and such are welcome also. Tell me your experiences!