PocketMatrix

This might be better in general discussion.

I can't help you otherwise, although I have plans to look into trying some head-to-head type multiplayer games using it, if that sort of this is possible. I'm not too sure if its any more complex than what you have in a remote control, and I'm pretty sure remote controls are one way only, in otherwords you can send, but not recieve.

I'd say you'd sooner see wireless as a better solution since that sort of thing doesn't have to be rewritten and uses already present networking code. Whereas the infra-red I can't off-hand think of any available libraries.