Centipede Shield - also a contest!

Lots of good ideas so far, glad so many of you think this might work for your projects.

Based on the entries so far, I want to clarify a few things.

PWM may be possible, but probably not too accurate over I2C. I would say that if you're controlling LEDs, you should plan to just have them either on or off. The same goes for LED matrix driving...it could work, but there are probably better and more reliable ways.

Since these are general purpose I/O, I'd like to see at least some mixing of functions. Input-only and output-only are valid uses for this board, but don't exploit any advantages this would have over some shift registers.

I am also paying a lot of attention to how the entries are written, and really appreciate the ones with full details and examples of what you've already done to work on the project. From these posts, it's pretty easy to tell when someone knows what they're doing, and has the ability and motivation to follow through. I would really like to get feedback on these and not have them sit on a shelf until the Arduino is obsolete. If any of you want to expand on your project a little more, that's fine. Feel free to post more details, as long as you get them in by Friday the 13th they'll be included in the overall decision.

Thanks to everyone so far....