http://youtube.com/watch?v=ynEC22zI600
i'll let you decide wich ones are glitches and which ones are legit (i think both are featured in the vid). but i think that the cluster of builings up north that you are talking about is simply jumping onto a dumpster on the West side, then looking at the window, and hitting X to climb. there are some really cool places in this game that can be easily jumped to, people just dont. I remember plenty of complicated jumping patterns that no one thought were glitches in Socom, the problem is that COD is so new that people still dont know about the jumps.
dont get me wrong though, some of these jumps CAN and DO lead to glitches. just gotta be carefull.
if anyone wants to know any cool jumps (not glitches) hit me up with a PSN invite, and we'll private match it up!