I would swear I saw an Instructable on this somewhere, but now I can't find it. I have an old corded telephone that I want to rewire. I just want to take the actual handheld part and attach it to a standard 2.5mm stereo output, such that I could either plug it into a cell phone and have a giant cool headset, or use it with my speaker/mic splitter to do VoIP-type work on the computer. Do phone cords have standard colored wires? Am I just going to have to figure it out myself? The headset has a standard 4-contact CAT-1 phone jack, and I want to take one end off a phone cord and replace it with a 2.5mm plug.