Have you heard of the Griffin SmartDeck? It’s quite possibly the best iPod accessory that is also very practical and reasonably priced.
For just $30 you get a cassette adapter that listens to your radio and tells the iPod what to do! You can control the volume and playback of the iPod.
Use the cassette deck’s forward and rewind buttons to advance to the next or prior songs in the iPod playlist. Pause and stop buttons do what pause and stop buttons are expected to do. Hit the cassette deck’s Eject button or switch from Cassette to Radio, and Griffin’s SmartPlay technology automatically pauses the iPod.
Now only if I had a tape deck in my car.