Here's a few for you 6FL (iPod interface) customers.

*Press the volume button in and it pauses the iPod (not just muting, like radio)

*If you press and hold the up arrow on your steering wheel, it will jump ahead a few seconds. It will fast-forward if you keep holding it down.

*If you have the voice activation, press the button and say "iPod" and it will take you directly to your iPod. (undocumented feature!)