Automatically start/resume rendering animation when computer is idle

So my idea is quite simple and similar to the system that Folding@Home uses:

You got a checkbox in Blender, where you can set your render to start/resume rendering an animation as soon as the computer is idle (Screensaver or Windows turn off display event happened). As soon as you come back to the PC and move the mouse or press a key, Blender immediatly stops rendering and saves the number of the frame that Blender was working on. If the computer is idle again (and Blender still runs in the background of course), it restarts rendering at that frame.

Of course you get a little overhead from the frame that gets discarded when the render gets aborted mid-frame, but i still think it's a vast improvement of comfort for people who use their work/private PC for rendering.

Let me know what you think!