What I am looking for is some car/portable audio stuff. Specifically, I need a gadget that will allow me to plugin a USB drive and then play the MP3s on that drive through my car stereo (or really any other device). So, it takes a USB plug as its input, decodes (and displays) the mp3 info, then outputs it through a regular mini-plug port.

Better than that would be a car audio head unit that would take the USB input directly. That would save me some hassle.