Now when you choose an AirPlay-compatible app, you’ll find your just-added Sonos unit among the destinations. Select it and whatever you’re playing over AirPlay will be channeled to the Sonos units of your choosing.

This solution is built with iOS devices in mind. Although AirPlay is also available from your Mac via iTunes, there’s very little reason to use this setup with content from your computer—Sonos lets you stream your iTunes library directly so why go through this rigmarole? And that’s just as well because if you attempt to use AirPlay within iTunes to stream to the base station attached to your Sonos unit as well as other destinations (another AirPort Express or an Apple TV, for example) you’ll find that the music plays out of sync between the destinations. Also, this is a solution for audio files. Although you can send the soundtrack of a movie or TV show from your iPhone, iPod touch, or iPad to the Sonos base station, the video and audio will play out of sync.

Those familiar with Sonos systems may consider that this solution can act as a replacement for the company’s $119 ( Macworld rated 4.5 out of 5 mice ), a product that lets you stream the audio content of iOS devices jacked into the dock. The two solutions differ in a few ways.

The first is that the dock is more ideally suited for audio that you intend to play for a long time—an audiobook, an MLB broadcast, or an evening’s-worth of music. Try to do this via AirPlay and your iOS device’s battery will be drained in a few hours.