cool project ideas for a cable modem?

I would sell it on eBay.. I have never heard of any cool hacks for them if you don't actually use it as a modem.

Sell the modem and buy a kit from http://www.solarbotics.com/ and build a BEAM robot. I'm a total nerd and love building little robots. It is a great way to kill hundreds of hours.

I did not see any projects in a quick glance at my favorite busy body website www.i-hacked.com for your model. You could check for general modem projects, but you very well might be wasting your time when the ebay, robot option is so appealing.