I have this paired with my desktop PC and my iPhone 4. Out and about, I can keep my phone safely in a zipped pocket in my bag an control my music with this.
The absolute best thing about this receiver, is being able to use your own headphones with it. I have a fantastic pair of headphones that I didn't want to stop using, so this is excellent.
It pairs up with my PC nicely too. I can clip this to the outside of a pocket or my belt and have my music/movies playing on my PC without fear of tripping on wires, plus I am able to leave the PC to walk around the house and still have my music playing in my ears.
I toyed with the idea of just getting a wireless headset for the PC, but with a bluetooth dongle I plugged into it, I can turn any pair of headphones into wireless ones.
In short, this product is fantasic; very practical to have and very easy to use. So glad I bought it!