These days FM transmitters are a popular way to connect MP3 players to car stereos. Typically these are low power devices with ranges of just a few tens of feet. However, except for the FCC, broadcast spectrum law and voided warranties, there's nothing stopping you from upping the range on your transmitter and starting your own travelling pirate radio station. If you own an iPod and a Griffin iTrip, start with Engadget's how-to. Next, prepare your marketing materials ([Via BoingBoing]). And finally, solder yourself an antenna amplifier (also [Via BoingBoing]) for the iTrip and you're ready to go.