I'm going to put my own demo in this zipfile, it contains more jumps you can do at the rooftop which allows you to go out of the map. Credit for Louw.
This is the seperate demo which I'll be putting together with the other 2 and more jumps on the site tomorrow:
http://rapidshare.com/files/14592242/ou ... .dm_1.html
Also, I found a way to get on yet another rooftop, it's fairly easy but my FPS prevents me from doing it. Another link will follow later.