This plugs into a USB port for power and receives audio from anything that transmits over Bluetooth. Plug your speakers or headphones into the 3.5mm audio jack and you can convert anything into a wireless receiver.
Shows up as a standard bluetooth headset/speaker under OSX, Linux, windows ... no configuration or drivers needed!
I was using it with the USB power adapter shown to stream music from my laptop to my sound system from anywhere in the living room. Worked great!
NOTE: it does NOT stream audio over USB. The USB plug is for power ONLY.
$10 for the receiver alone or $12 if you want the power adapter too.