Using Android phone as Bluetooth headset to PC I'd like to use my HTC One S (running Android ISC) as a Bluetooth 
"headset" for my computer, so I can use it to make VOIP calls.

For devices without that capability built in, are there computer/phone applications that make this possible? Wo Mic is a start, but only supports the voice input, not output.
Why not use the Google Voice application for Android?  It can be found in the Google Marketplace.