[EricH]

I decided to look into what this year's rules have to say. I found one "debatable" against:

<R64> The radio modems provided in the 2008 Kit Of Parts are the only permitted method for communicating to and from the ROBOT during the MATCH (except as noted below in Rule <R65> and Rule <R84>). Radio modems from previous FIRST competitions must not be
used. The radio modem must be connected directly to the Robot Controller using one of the DB-9 cables provided in the 2008 Kit Of Parts. No other form of wireless communications shall be used to communicate to, from or within the ROBOT (e.g. no Bluetooth devices are permitted on the ROBOT).

I say this is debatable only because the rule is referring to wireless communication, not necessarily energy transfer.

However, it may also be legal:

<R68> Additional electronic components for use on the ROBOT must be either COTS items, or assembled from COTS items. Additional electronic components include any object that intentionally conducts electricity, other than Innovation First Inc. relays and speed controllers, wires, connectors, solder, and fabricated printed circuit boards.

I think, if you made adequate provision for isolating the frame and a wired communication to the RC, you might be able to convince the GDC to allow it. However, I also think they would be more likely to not allow it.