composite from 6 seperate photos of the same scene but a few seconds apart from each other since i don't have the timing skillz of a muur88...;)
as requested by iraklis here's the "technique":
put your cam and wide angle lens (i wish i had a 10-20 or something in that range that is wider than my 20mm prime) on a tripod or something stable (i put it on a high concrete step for this one) and just fire away as the people walking by. just make sure you don't change the position of your camera, the focal lengh if you have a zoom, the focus and the exposure (put everything on full manual) and make sure the light is not changing while you do the series! then in photoshop just select the pics you think contain interesting people or situations and combine them by overlaying them and masking the parts you want to see in the final frame. basically the same technique that you use to do these multiple self portraits: