If someone were to ask me who the masters of virals were, Guinness would probably come somewhere on top of the list (along with Nike and a couple of the other staple brands).

They've long proved that their adverts have been a massive success, both online and off. This well-known one by BBDO, is a little different to their normal offering, but still manages to hit the spot with a cool idea, some trinkly music and a pretty light show:

Personally, I think most city skylines could do with a nice addition like the above.