Best Flashmob Ever? [VIDEO]

Maybe you have seen them while surfing around on the Internet--flashmobs. It's when a group of people gather together in one place to sing or dance in a somewhat busy place, like a park or a mall. I've seen a bunch of them, but there is something about this one that was amazing. Maybe it was the song, or, maybe it was the reactions, but I think this is the best flashmob video I have ever seen. Check it out.