The number one requested feature I have received since the launch of Lock Delay has been a "Lock Now" home screen widget.
In fact I would love to use this feature myself. I even went as far as I could in the implementation. Unfortunately, the Android SDK presents a bit of a road block. There doesn't seem to be any way provided for apps to forcefully shut off the screen. Without that ability, the widget would not be useful.
I'm hoping to be proven wrong here so if anyone knows of a way to programmatically turn off the display and sleep the phone, PLEASE contact me through my Google Profile