
AKA, there are various 3-ring adapter cables sold for camcorders and such. Some will work, and some will not, depending on whether ground is on the 3rd ring or the 4th ring of the plug. I am using one from a Sony camcorder and it works fine. NOTE: On the Sony cable, the headset outputs are NOT on red and white, I believe they're on yellow and white, and the red is mic input. Colors will vary by brand, you need to test.
Also note, using the earbud jack, you can only get mono input (and of course stereo output), because there's only one mic contact available. For stereo, you have to use the dock port, which has stereo analog line in and stereo analog line out.