In case you haven't seen it, Future Pinball is a set of software tools that let people build their own pinball tables, from modeling the table itself to setting the rules of play. It's pretty intense, and way out of my league. I caught this video over on Offworld, and it's a super-awesome implementation of Future Pinball using a big HDTV and a second monitor, used to emulate the backglass.
Wicked. Considering how hard it is to find parts for my aging Earthshaker machine, stuff like this can make for a reasonable substitute... but then, I've always had a soft spot for digital pinball when it's done right.