Shake to Shuffle is a neat feature that takes advantage of the accelerometer, a sensor that allows the phone to know when and how it is being moved by the user, built into the iPhone and some iPod nanos. This feature, which was introduced to the iPod/iPhone line with the 4th-generation iPod nano, does very much what you'd guess: by shaking the iPhone or some nanos, you're able to shuffle the songs you're listening to and get a new, randomized playback order (curious about whether the iPod's shuffle feature is truly random?).
Enabling Shake to Shuffle on iPhone
Shake to Shuffle is normally turned on by default in iPhone OS 3.0, but if you need to turn it on for some reason, it takes just a few simple steps.
1. From the home screen, choose Settings.
2. Then scroll down and choose iPod or Music (on iOS 5 and higher).
3. The first option is a slide for Shake to Shuffle. Make sure the slider is moved to "On" to enable the feature.
Using Shake to Shuffle
In order to use Shake to Shuffle, you'll need to be listening to a song in the iPod app of your iPhone (it doesn't work if you're just looking at your music library. A song actually needs to be playing). When you're ready for a new shuffle order simply grip the iPhone tightly (after all, you don't want to shake it out of your hand and across the room) and shake it firmly. A side-to-side shake works fine. So does up and down. As long as the phone senses movement, the feature usually kicks in.
With a sufficient shake, you'll hear a bloop come from the phone's speakers or through the headphones and, after a very short delay, a new song will appear on screen and begin playing.
Shake to Shuffle on iPod nano
Shake to Shuffle is supported on both the 4th-generation and 5th-generation iPod nano. To enable it, do the following:
1. From the home screen, go to Settings.
2. In Settings, go to Shuffle.
3. Click on the center button of the clickwheel to scroll through options. These include shuffling songs, albums, or turning Shake to Shuffle off.
If you've turned it on, just give your nano a good shake it and will begin playing a random set of songs.