Mini Wireless Bluetooth 2.0 USB 2.0 Adapter $1.49 shipped.  Note that you can get two for just $2.09 shipped as shown here.  This Bluetooth USB adapter works with Bluetooth v2.0/v1.2 compliant devices including notebooks, PDAs, handheld PCs, digital cameras, printers and mobile phones.  Note that it may take a while to receive your order.