Leo says that it goes back to Steve Jobs who hated on/off switches. So the displays have no buttons. There is ResX, which could control it, but likely won't turn it off. Someone should write a program or script that would do it, and there may be an app in the app store already. There's an app called "Should I Sleep?" But that only keeps a monitor on. There's always a power strip with an on/off switch to kill the power.
The Chatroom says that iGo makes a product that may do it.
Peter would also like to burn DVDs, and Leo says that iMovie is an easy choice that he already has.