I was steered toward Plantronics by a friend.  He was definitely right.  Very clear, easy to use, comfortable, compact, qick charge time, and great battery life.  One tip - I didn't know for a while, but your volume control on your BlackBerry itself will raise and lower the volume on the headset.  If your phone supports bluetooth, you have to get a headset.  There is no contest between this and a wired headset - in sound quality or usage.  And the Plantronics is a great choice.  I have only used another(Motorola), and this seems to keep a better battery charge and the headset is much more comfortable.  You have to remember you have it on sometimes or you walk into a meeting looking foolish.