For thoose of us blessed with iphone's, or ipod touches, there is a genuis piece of software called CF iViewer, free on the app store, and with a quick registration (also free) on their site, download the program directed too, download the plugin listed and voila youre off. This does ofcourse require either a network or an ad-hoc network. It works very much like Remote from APPLE, u can see what artists to pick choose playlists, all of this and its quite quick, definately on of my top input devices for a carPC, usefull especially at meets as u can stand outside the car and show off by changing tunes, increasing,decreasing volume etc.

There is a great walkthrough manual on their site but any issues let me know and i can help