?xxAMxx? showed photos on a thread Ultimate Headset until they release a BT headset for the N800. S/he had removed the pendant cover and soldered in a good headset. I can't hear anything on the N800 headset. When I hold the N800 to my ears for a long time then I cannot sleep. Maybe it has something to do with 2.4 GHz. I have heard that 2.4 GHz is also the wavelength for a microwave oven.

Perhaps someone could take a look at those photos and ohm out the soldered posts with the 4 rings on the plug. Maybe this would help us determine what ring is doing what.

I used to do things like that. But now I am buried in tsunami/earthquake relief. The N800 is a great help in this. If you are interested please see http://oouc.wordperfect.com.

In relation to using the headphone jack, I had been wondering if it is OK to plug an ordinary headphones, (3pin, 3.5mm stereo jack) into the audio-out socket... and the following post says that it is:
http://www.internettablettalk.com/fo...hlight=headset

(also useful for connecting to desk speakers, stereo etc)