Not sure if this is common knowledge because I've never seen it discussed. I just discovered that Vol + or - if held down will wake the phone up. I had to try it on my D1 and D2, and neither had this feature. I usually use those if I the screen sleeps and I need to wake it right up. Doing that brings me to the last screen I was at if done quick enough. Apparently on the D3, even after sitting for a while the Volume buttons will wake it up to the lock screen though.