Tired of having a couple of cables unused behind my dash, I made up a Y cable, two RCA plugs to a mini stereo phone jack, and attached the RCAs to my sled's aux inputs and mounted the other end inside my glove compartment. (I have an E30 BMW 325e, which has a gaping maw of a glove compartment.) Now I can hook up a variety of portable players and play it through the Aux inputs. Very nice. (Now if I can just figure out what the hell the empeg's screen is telling me when in aux mode. I'm sure it's in the FAQ.)

Anyway, it'd be really nice to also be able to hook power up to said portable devices, but I'd have to have something that would allow me to change the voltages so that I could hook up different devices. I suppose I could hook up a variable resistor of some nature, but that seems like a bad idea for a good number of reasons. Being able to attach a real device that does that would be super, but I can't find one that has an appropriately small selector. RatShack's seems to have a dial about 2" in diameter. Anyone have a solution for me?