The solution was the , a $50 Bluetooth receiver that implements the , a streaming protocol that can connect mono or stereo audio sent from one device (such as a computer, smartphone, or an "i" device) to an output device.
The A2DP spec is now widely implemented so you'll find support in all sorts of proprietary devices and a number of operating systems, including 1.5+ devices, Apple iOS 3.0+, OS X 10.5+, and 7.
You plug the audio output from the Music Receiver into your stereo, plug the supplied wall wart in, and the Music Receiver temporarily goes into pairing mode. Use your sending device's Bluetooth controls to search for the Music Receiver, , and that's it. On the sending device choose the Belkin Music Receiver, and voilà!
You can pair up to eight devices but only one at a time can be connected to the Music Receiver. This means you have to explicitly disconnect, say, your iPod before you connect your iPad, otherwise the iPad connection will fail and, it must be said, fail rather inelegantly. Let's hope future renditions simplify the task of changing A2DP connections to a true consumer level of simplicity.
The Belkin Music Receiver works flawlessly with my iPad and my Droid Incredible (still my favorite cell phone so far), but when I touch the device to the back side of my iPod Touch while it's playing I get "dropouts" ... I suspect the Bluetooth antenna is located there so my high-tech solution? Don't put my fingers there. Yes, it's less than satisfactory on the part of Apple, but otherwise the setup works great.