I have a Rio Karma. It cost me about $250 for the 20gig from amazon.com. In my opinion it is much better than the Ipod. The Karma is smaller, and has many more features. The ~13 hour battery life is great for the car. It also comes with a small dock that has rca, ethernet, and usb 2.0 output. It comes with the corresponding cables to. So, is your HU has aux. input, you would be all set with the Karma. You'll love the Rio DJ too. Just set it to "Entertain Me" and no fumbling with it while driving. Check out the forums at
Riovolution 
