haha that vid is retarded, shitty audio...
but another thing you can do is ghosting, u just walk as close as u can behind someone with out them noticing for as long as u can, u just be their shadow. me and my friend are gonna make a video of it when he gets back from America
here is how ghosting was made....
YouTube - ROVE - Hamish & Andy - Personal Space Invading - Ghosting