Step 1: Parts You Need
A 2.5 mm head-phone jack with a few feet of cord, an old pair of ear phones will do the trick.
A circuit board, I used one that I had de-soldered and sanded the printed circuit off of.
A 2.5 mm jack receiver, I de-soldered this one from an old cd player.
And some form of enclosure, an altoids tin would be ideal but i didn't have one on hand, so i used a piece that i pulled out of a broken VCR.
Step 2: Tools Required
Dremel (optional, depending on enclosure used)
Step 3: Place Parts
Step 4: Solder the Cord
Separate all three wire
Burn the tips of each
Solder it to back of circuit (red should be right, blue left, and copper ground)