I'm very interested with that kind of projects, but I'm always wondering what to do once the hardware part (and software controller) is done. By that I mean the artistic part of it.

For example, take this sculpture: http://vimeo.com/21904379. I was thinking it could make for a very cool sculpture at home. Hardware-wise, it's very straightforward, but I wouldn't know what to hook it up to software-wise and how to show interesting patterns.