Richard Davey points out two new interesting PHP commands he discovered when looking through the graphics (GD) section of the manual - imagegrabscreen and imagegrabwindow.
Upon further investigation both of these commands can be used to take screen shots of the desktop of your server, or any applications window (such as a web browser). Both commands are listed as being "Windows only" and also possibly only in CVS, but I found both of them are in the 5.2.3 standard release and compile without error. However at the moment neither appear to actually do anything other than return fully black images
In testing the functionality, though, his only results were black screens and images instead of the expected image results.