Last week I bought a set of these headphones as I thought it'd be awesome to use them for both Bluetooth Audio and also for making and receiving calls!
They are absolutely fantastic! The sound quality over Bluetooth is pretty good (but not as good as cabled) and I've had it seamlessly switching between making calls and then listening to music!
They came with a BT adapter for using with devices that don't support A2DP so you can just plug the 3.5mm adapter into the socket of the device.
As I was using a Windows Mobile device with AKU 2.0 on it - I didn't need the adapter!
The only real downside to the headphones are that the microphone is pretty discreet so you do look a bit mad wearing a seat of headphones talking to yourself!!