Newegg sells the Yamaha NX-B02 Bluetooth Wireless Speaker for a Web low.  These speakers do wireless over Bluetooth and are compatible with players that have A2DP.  They have Dual 4.5cm (1-3/4″) Speakers for Stereo sound, a built-in battery and 5w x 2 built-in amp.

It’s $169.99 – $130 instant off + free ship = $39.99!