This looks very promising:
http://www.atarimax.com/usbcoleco/documentation/
Yesterday I pre-ordered one for myself. I have thirty games for my Coleco and would like to collect some more. This cart will help me decide what I should go after first as I've been having problems finding a good emulator for the Colecovision. I really hate buying a game before I try it. It's a dream for programmers too. 
Er, I can't program at all though.