Mouse Lock to Window

I have a really bad habit of moving my mouse outside of the window (in windowed mode, obviously) when I get into it and accidentally clicking outside of a window, and focusing another, is detrimental to me.

I'm suggesting an option to enable (off by default?) locking the mouse inside the bounds of the window.
This should be trivial (I'm hoping, of course nothing ever is) in SDL, as from what I've read it handles it for you, even if you're locked at a framerate with a monitor at a higher frequency; see: SDL_WM_GrabInput( SDL_GRAB_ON );

source: http://sdl.beuc.net/sdl.wiki/SDL_WM_GrabInput