The Droid has the TI wl1271 wireless chip which is capable of transmitting and receiving FM radio signals, the Motorai uses the same board and comes with this functionality. Several devs over at Alldroid have enabled the hardware (they are pro with linux) but haven't been able to write a real app that takes advantage of it. Such an app was written by a dev for a different phone and I believe that they are trying to convince that guy to port it to the Droid.
See the poll and thread at Alldroid here: AllDroid - View topic - Droid FM Radio Thread
See the poll and thread at Alldroid here: AllDroid - View topic - Droid FM Radio Thread