Those are almost certainly test points for the designers, and may yield interesting results if a serial terminal (with suitable level converter) is attached to them!

Is there any way you can take some photos of the headset and post them to the forums? That might help me see if there is a way to remove that membrane switch.

Thanks for being the first to crack open one of these headsets!

The headset looks as though it should be fairly easy to convert. Power switch is a slide at the edge of the board, with three visible leads. Volume up/down is a separate membrane switch with two buttons that can be desoldered and replaced. If the board is mounted at the back of the handset handle, the built-in LED could be visible through a hole and the noise-cancelling mic could hear through another opening.

The only sticking point may be the pick up/hang up button, which is a membrane switch near the top center of the circuit board. It’s tucked between two ICs; I have a feeling that it may need to be destroyed in order to find points to solder to. Any suggestions for doing that?

One other interesting thing – test points on the back of the board for VPLUS, VBAT, GND, RTS, CTS, TXD and RXD. ISP access for the CPU, maybe?