I know it's probably on here somewhere but I am looking for a device that allows the input of an audio feed from more than one source. I have a cell phone with built in GPS and an I-pod that i want to send the sound to a set of earphones from. It needs to have priority of one source and switch automatically when the sound from the phone comes on to cancel the i-pod sound and then switch back automatically. All suggestions are appreciated. Price is an issue but I want it to work.