Targus USB Bluetooth Adapter for $6.99 Shipped

Targus USB Bluetooth Adapter for $6.99 shipped.  Note that it comes in OEM packaging, which means no pretty retail box and marketing materials but is otherwise identical.  This is a silver Bluetooth adapter and connects up to 7 Bluetooth-enabled devices at a range of up to 33 ft.  At the time of the writing, all 4 user reviews have given it 5/5.  Most places have it for over $20.