The only thing I have heard of is Rockford Fosgate media changer. It takes 8 multimedia card ( I think they are just Flash Media cards). The problem with that is that the unit is expensive, and, each flash card is expensive. I think they were aiming it at people with portable players that support flash cards, they could just pop it out of their portable and into the changer. Check it out at Crutchfield.com. $250 includes one 8Mb card.