Stereo headset on the Treo 650.
With this software from Palm for about $20.00 you will be able to fully use the Motorola HT820. I just purchased it and it works PERFECTLY!! You can listen to all your MP3's on your phone or expansion card AND receive and talk on your phone!! It has a built in microphone in the headset!! This is the coolest bluetooth devise ever made!! I love it!! Trust me I took a chance and it PAID OFF!!