Anyone tried them?
http://www.koss.com/koss/kossweb.nsf/Cobalt

Seem that it work with computer , bluetooth phones and Mp3 players.
I am so tired of wires breaking on headphones
but so far a reliable good sounding wireless for mp3 players has been nonexistant. (i think sony has something but dont think sound good)

But now Koss release Cobalt.
a behind the neck headphones (dont look too big either which is good)

Only plug a Usb-device on back of your computer and your headphones
work, or plug a device on mp3 player (probaly work with Md player too?)
and headphone work.

My question is :

1. How is the sound of this headphone
2. Can ambient sound (cars, people, other mobile phonets etc..)
intefere much with bluetooth signals?
3. Will this work with Samsung mp3 players and Minidisc players?

I know nobody ever cares about this unpopular cautious attitude, but stay away from wireless devices as most as possible for long term health issues; certainly for continuous exposures as with music i.e. wireless earphones. (keyboards etc...)
Everything emitting electromagnetic waves aboves 2.4GHz can be potentially cancerous to the human body.
Now obviously no-one will settle without the mobility the mobile phone gives us, the freedom & information internet, Sat TV provides, but stick to the absolute necessary, don't have the emitter or receiver too near your body, and specifically near vital zones of your organism.