I love the folks from Improv Everywhere. After invading a Best Buy shop with a crowd of seem-to-be-employees, they now slowed time in a Home Depot shop
We would sychronize our watches and then walk over to Home Depot and shop. At exactly 4:15 we would all begin moving in slow motion. We'd do that for five minutes, and then shop normally for five minutes as if nothing had happened. At exactly 4:25 we would all freeze in place for five minutes. When that was over we would go back to normal and eventually leave the store.
It's hilarious to see the reactions of other shoppers and the shop employees. I'd love to participate in something like that some time.