I bought the plantronics 640 for my dad about 6 weeks ago. My dad is in a wheelchair, so I've been trying to sell him on a bluetooth headset for the past two years. He was afraid that he'd look like one of those self-important a-holes that rolls around like a handycapped version of Gordon Gekko. I assured him that the 640 was the smallest and most inconspicuous bluetooth headset that I could find and it wouldn't make him look like like a cyborg salesman. He finally agreed to give it a go.

Here are the results: He loves it. The wind noise that alot of other internet reviews spoke of doesn't seem to be a problem for my dad...and he drives with all his windows down (no A/C). The headset itself is so light it practically floats. I couldn't believe that there was a battery inside of the headset...I was looking for a battery case opening for 5 minutes before I realized that the battery was built in...it's that light. You can pair the device up to two things simutaneously if you want (ex: your computer and your cell phone), though my dad has no need for that. His only complaints: you do need to charge it up every night if you talk often. If you talk really often, you should bring the portable pocket charger (which is still quite convenient).

I personally have no need for a bluetooth headset myself, but if I did, I would definately get this thing because it's tiny, it's light, it's inconspicuous (well, as inconspicuous as you can get until Jack Bauer starts endorsing his magical in-ear CTU issued earpieces), and plantronics obviously knows what they're doing. This is definately a headset for mobile users though. If you yap on the phone all day at work or home, you need a headset that has longer lasting batteries.