I have used this headset with my Treo 650 and have been very disapointed with it's performance. It may be a function of the Treo's Bluetooth capabilities so keep that in mind and do not waste your money on this headset if you are using a Treo.It has very poor range; arm's length at best. Outdoors it is useless. It has times when it will refuse to pick up a call. The voice quality is also poor with hissing and crackling. The only place it seems to be remotely useful is in the car where it is within arm's reach and the hissing is only moderate. This is pretty expensive to only be able to use part of the time. Talk time is also much shorter than advertised.My $.02, save your money for something else.Update: Recently purchased the new Treo 650 headset by PalmOne. That is the new Bluetooth 1.2 version, not the clone of this Jabra. Much, much better. Now I have a headset that I can use all the time. I have completely replaced all my wired headsets.