We used to use the CNC Plasma cutter back in school quite a bit, great tool. It was great for rapidly producing pieces, and your imagination is your only limit.
I saw this tool recently and was impresses with its detail:
With something like that you could pump out personalized parts rapidly, and really make some money.
Ill have to stop by some time, I graduated the GM training program, but I had 2 years of CNC training as well, could chat your ear off about CNC.