I have owned a Treo 650 on and off and on again since this model came out.  Initially, I was extremely frustrated by the phone's telephone performance and its lack of stability.  Frequent reboots, freezes and dropped calls made it difficult to appreciate the phone.  I ended up getting rid of it and relying on a separate palm and cell phone.  Over time, PalmOne has released firmware updates (the phone's operating system) that have made the phone very stable.  The improvements we so significant that they actually won me back.  This review is for the GSM Treo 650.