a way to make an app that runs in tray that pauses or freezes the screen (and unpauses) on a keypress?

Question

I cant seem to find anything on this.. Does anyone know how this could be achieved?

I'd want to freeze the entire desktop with a single keypress, then undo it with the same or different keypress.


(windows app, win vista or win 7, x86/x64)..

Thanks