All you have to do is go to your local avionics shop and buy a standard aviation MIC jack. Take it home and splice it into an old headphone cord (in lieu of the headphones) and viola.... plug the headphone jack into your MP3, walkman, iPod, etc and the MIC into your Cockpit Jumpseat AudioPanel (with the interphone hot-mic on) and you are now ready for tunes (without any cut-out during radio transmissions)... I've been told that an electric guitar jack works as well....
Tailwinds-
Pappy