Here’s a list of freeware softwares that allow you to redirect sound from your Windows Mobile Pocket PC’s loudspeaker to a mono Bluetooth headset thus providing unofficial A2DP functionality to your mobile device.

This can be useful in situations like when you want to listen to Skype calls on your Bluetooth headet instead of from a loudspeaker in a public place

Download-
1) BTAudioToggle

2) Bluetooth Sound redirector from XDA forum- works with WM 5

3) Bluetooth Audio for PPC 6700

4) BTAudioNav from ToDoPocketPC forum

I havent tested any of the programs. So you are free to try them at your own risk.