A P90 Plantronics Bluetooth ear-piece meets your qualifications. You can pick these up at most Wal-Marts for around £14/$20. I'm sure Amazon has a few as well, and you could probably get a better deal from there if you're tight on cash. I have purchased this and love it. It was specifically designed for the PlayStation 3 system. It has about an 8-hour average battery life when left on continuesly. Overall it's a great device and I recommend it.
I use the Sony headset for my PS3. It works great. On the down side it get really uncomfortable after 3 hours of playing. The battery life is great and the design is mini and feels good on the face. Its also easy to set up since it was really designed for the PS3.