$50 Gift Card Toward Something Bluetooth

AT&T gave me a $50 gift card for signing up for their DSL.

I want to put it toward purchase of a some wireless/cable-less device that
will talk with my computer.

I was thinking of some ear/headphones that allow me to walk around in the
workplace without having my laptop speakers disturb others with the music
or political talk radio that streams in on the Net.

Or maybe there's something more sensible (?), like a Bluetooth mouse (I
don't use the touchpad since it gets greasy from my finger oil too
quickly).

Then again, I suppose a BT speaker system with good wattage, because
sometimes I got a DVD running on my laptop (the vid output on its 17-inch
UltraBright screen) and the speakers are elsewhere and fill the room.

Please help me out for a gift idea for myself.