With OS 3.0 or later, iPhone 3G, 3GS or iPod Touch 2nd generation can be paired with a Bluetooth output device such as stereo headsets or audio receivers. This allows Tuner2 to output audio direcctly to the paired Bluethooth device.
Simply touch on the Bluetooth icon on the right of the volume slider for the "Audio Device Selector"
The Bluetooth icon appears only in iPhone 3G, 3GS or iPod Touch 2nd generation with OS 3.0 (or later) and when the Bluetooth device has been paired with the iPhone (under Settings > General > Bluetooth).
In this instance, we paired our iPhone 3GS to Sony Bluethooth Transmitter & Receiver (HWS-BTA2W) which connects to a home entertainment system via AUX input. It sounds great. (This can also be done with many automobiles with this feature.)