iTrip FM Transmitter for iPod
Believe it or not, some of us still like to listen to the radio. Pop music radio is awful (especially if you have iPod -- why would you bother?). But if you like news stations like NPR, or sports, it's helpful to have the ability to pick up a FM signal. Instead of carrying some other portable device for this, now you can plug a little receiver into your iPod, and voila!
simple. small. wireless.