Are you forever running out of battery on your iProducts? Charge them up with the iPhone USB Cable. There's never any harm in getting an extra cable for all those times when you really really need it! Keep one with you in your bag, or at work or just keep one for your laptop!
Of course if you have an iProduct, you'll know that this cable is also perfect for data transfer, so plug it in and start moving those music and movies.
So get yourself an iPod iPhone cable, it really will come in handy.