After putting it off for way too long, I picked up a Black Motorola HS850 Bluetooth headset for my Treo 650. It’s simple to use and pairing it with the Treo 650 wasn’t bad. However, the range is really poor: if I wear the headset on my right ear, and put my phone in my left hand and extend my arm all the way out to the side, the headset becomes nearly unusable. Also, even with the phone and headset volumes maxed out, the audio is still too quiet at times. These all seem to be known issues in general with Bluetooth headsets and the Treo 650, unfortunately. I still really like the Motorola HS850 headset and would recommend it, but perhaps not if you’ve got a Treo 650.