This is my second purchase of the Plantronics Voyager 855 - I bought it so that I'd have a fully-charged spare when I wanted one (such as long-distance flights).  I use this daily with my BlackBerry Storm to listen to MP3s during my cardio workouts and when traveling on airplanes, as it does a fair to good job of blocking white noise from the jet.  Other than othe ccasionally (rare) cut out (break in the BlueTooth transmission stream), it works flawlessly.  The sound quality is very good, though perhaps not up to the standards of an audiophile listening to high bit-rate audio files, and you can't beat the price! I'm going ot buy additional sets for my wife and kids to use with their BlueTooth-enabled cell phones. Definitely recommend.