From what I've read, Actor Matt Frewer was fitted with contacts and a makeup head appliance, and video bluscreened in realtime. The moving BG effects were composited in later, along with the trademark periodic stuttering edits. In some live "interviews" with Max on TV, technicians did this on-the-fly with a live composite and digital sound delay. Every now and then some stretching and squashing of his image would also be done with digital video effects (DVE). As far as copying him goes, The name and exact likeness are trademarks, but I've seen lots of parodies of him, in everything from Doonesbury to Back To The Future.