[stalemate1]

According to wpcentral, windows 8.1 has this feature.

See:
Windows Phone 8.1 Features | Windows Phone Central

Here's a copy and paste:

"double Tap to Power Off"

Here's a screenshot: (point number 4)



So how do I enable double tap to Power Off ?

[hopmedic]

That looks like a typo. Power on doesn't appear on that page, but double tap to power on is one of the features. I have never heard of double tap to power off. In fact, you couldn't double tap to power off, because double tap is a gesture used by some apps, and you wouldn't want the phone to turn off while trying to use that gesture in those apps.

[Noahma]

missed the first line didn't ya OP.

"The Windows Phone 8.1 beta SDK has given hints as to what will be in the Windows Phone 8.1 OS. While features revealed in that SDK are likely to go to the final version for consumers, there are no guarantees."

didn't make the cut for this release. If its in the SDK, it does not mean it will be there, just may be something Microsoft was fooling with.