Just posting a message here for those who don't look at the PPC Software fourm. I have written an application that will transfer your Caller ID Announcement (From MSVC or any other program) that used to come thru the PPC speaker to you BT Headset. You can also use it to open a Audio path to your BT headset for listening to music, ect.
Check out this fourm for more details.
http://www.ppcgeeks.com/transfer-cal...set-t1559.html
I am working on a Treo version, that should be done by the end of the night.