I wrote some software to design magnetic loop antennas that you might find useful. It should be easy to make transmitter/receiver systems. Hey use a negative resistance circuit to make both a transmitter and a regenerative receiver. Look up lambda diodes etc.
I also just figured out how to push data into what I call OCT resonators. I did get a bit over excited about that but in the cold reality of the next morning maybe it is not so great. However the O'Connor transform should be easy to implement even on a microcontroller and could be an interesting pattern generator for robot motion (eg coordinated leg movement). You can also use OCT resonators for pattern detection. I think there is some pattern detection code somewhere in the old java code section, or ask me:http://code.google.com/p/lemontree/downloads/list