IPhone – listen to just the audio of a movie on an iPhone

I bought my wife a Sony Xplod (sorry, forgot the model number) and that works really well with our phones. I would assume that all Sonys work equally as well (if not better).

You can connect the iPad directly to your stereo using bluetooth. Or you can use AirPlay to stream audo to your iMac. However you cannot record anything while doing this:

While the "AirPlay - Bluetooth - HDMI" switch is on, an alert appears if you try to record an Audio Recorder or Guitar Amp Touch Instrument, or if you try to record a sound with the Sampler. You can turn the switch off from the alert.

From: http://support.apple.com/kb/HT4622