Snippet #775
The iPhone’s "shake to shuffle" feature suffers from a fatal design flaw: it doesn’t work if the phone is locked (as it normally would be if it’s in your pocket). To actually use it, you have to unlock the phone (either by sliding across the unlock slider and potentially having to enter your unlock code). Another workaround is to double-tap the home button to bring up the iPod controls, but by that point you may as well just hit the "Next track" arrow rather than shaking the phone (in reality, you have no choice seeing as "shake to shuffle" still won’t work until you actually unlock the phone). This makes the feature basically useless, in my opinion.