Over the years I've tried a fair number of wireless Bluetooth sports headphones and I've yet to come across one that's truly outstanding. Whether it's their performance or design, each model, even the best ones, tend to have some sort of niggling issue that keeps them from being universally...
Plantronics BackBeat Fit is a lightweight wireless stereo headset (with integrated microphone) that features a sweatproof design and decent sound; It stays in your ears and most people should find it comfortable to wear.
When you're running, the cord (around the back of your neck) does flop around a bit, which may bother some people; Would ideally cost closer to $100