Omega Speedmaster X-33 Skywalker has a power saving mode, which can be activated by pull the crown. This parks all the hands and turn off the LCD.

But I remember there is a way to do that with just a press of button(s), anybody knows how to do that?

 

Not exactly the same, but see http://forums.watchuseek.com/f20/omega-x-33-hidden-mode-1051362.html