Improv Everywhere is the cosmic balance to Gawker: a group of real-world performance artists who generally make people feel like the world is a magical place. And in this clip that's been making the rounds, they turn a little league baseball game into a major league match, with an NBC sportscaster, a Jumbotron, and I won't ruin the rest. See below.
Man, it's like those scenes at the ends of family movies I'd see as a kid where everything works out really well and I would get so thrilled that I'd be embarrassed for having such a pure uncynical emotion. God, I just realized where my lifelong unhappiness started.
Anyway read the mission recap, which explains how the improv group got NBC to help out.