I've found what could be a great deal on ebay: someone selling about 50 Motorola RF modems for $20 each. You can see the details (or lack thereof) if you follow this link. I'm hoping someone out there knows something about these. Could two of them be used to create a bidirectional wireless communication setup? I'm not finding too much useful information on Google.... If you have any solid info, please post, I would be greatful!