I currently have the MOTOROKR S9-HD headset and it's been the best thing ever for me! I travel a lot so it sees a lot of use. I've been able to work out with them and even run with them on. I've also had the older plantronics version which was convertible from mono to stereo by attaching an additional ear bud. Unfortunately, this broke within 2 months so I can't recommend it at all (plus, I think it's been discontinued).
All volume, player and call controls work.
One thing that you have to be careful of is sometimes the rubber in-ear thingys will fall off, so you have to be careful of that.
MOTOROKR™ S9-HD Wireless Stereo Headphones - Motorola USA
I bought these after my below purchase faled me, hoping they woul dbe as good as everyone says. They are not. Yes they sound good, but only if you push them into your ears. Otherwise they force themselves out just enough to eliminate all that great sound they were designed to deliver.
I have the MOTOROKR™ S305 Bluetooth® Stereo Headphones:
MOTOROKR S305 Wireless Stereo Headphones - Motorola USA
A little cheaper, but I have been impressed. Even on the phone calls! People hear me fine. I can't use them for driving though. Need a regular bluetooth for that.
I tryed these and after abotu 2 hours, my ears were in pain, returned none the less.
I was devastated after 2 failed attempts so I am back to my $40 sony wired headphones that sound incredible and provide stunning bass, something the BT ones failed on.
I guess the technology and comfort level is not there for me yet.