I'm retracting the post.

From a practical point of view, what are you trying to accomplish?

If you just want to turn the phone part of the phone off then you could use Toggle, although it wouldn't do this automatically. It would be a bit of a pain since if you decided to make a call you owuld have to jusp through hoops to turn the phone back on, agina you could do this with Toggle.

Are you just interested in increasing battery life? Try a couple of tests. Repeat a movie with cron on and off, and then again with Toggle turning just phone off.

Please don't mistake this as me being a smart ass, but please be more specific on what you want to accomplish.