We have covered plenty of awesome speakers and docks for iPhone here in the past. Not all of them can be used wirelessly though. Sending music from your iPhone / iPod to your speaker using Bluetooth is not that hard as long as you have the right tools. These 5 Bluetooth receivers make that possible:
Logitech Wireless Speaker Adapter: streams your audio from any Bluetooth smartphone. It saves you from having to attach your mobile device to your dock. Android is supported too.
CoolStream Bluetooth Receiver: a Bluetooth adapter with the 30 pin connector for your iPhone docking stations. It comes with Bluetooth version 2.0, supporting A2DP for better stereo sound.
Belkin F8Z492TTP Bluetooth Music Receiver: this is compatible with devices with A2DP Bluetooth enabled. It offers max transmission distance of 33 feet.
Aluratek AIS01F I-Stream DockFree Bluetooth Audio Receiver: another receiver you can use to play music from your smartphone wirelessly. The internal battery lasts up to 12 hours.
Bluetooth A2DP Music Receiver: a wireless adapter that connects to the Apple dock speaker and offers transmission distance of up to 10 meters. It supports A2DP V1.2.
There are a few other Bluetooth receivers you can use to get started with Bluetooth streaming. The above products have you more than covered though.