Default [Q] Turn off screen with a shortcut?

Just got the phone and love it.

I installed ADW Launcher EX v1.3.3.8 and now it does not recognize the "double tap" to turn the screen off. Double tap to turn screen on works fine.

I tried a few other launcers like Nova and Apex...same result.

Is it possible to create a shortcut that turns the screen off?

thanks