That's a very solid way of doing it.  Any ideas what subforum or site would have the most arduino programmers?

I conceived of this idea with the arduino since I know about it from my friends, but there could be other platforms that would make this simpler or faster to develop.  I'd probably want to stay away from mobile devices since they're non-dedicated and I'm guessing that trojans/rootkits can be written for them to target BC users