Wouldn't it be cool to...
Go back in time to when your favourite actors were kids, and you took a bag back with you that had a cell-phone, a digital camera and stuff. You could call them nerds and see how amazed they are by the digital camera and stuff.
You'd make friends with them and be, like, "Yeah, I come from the future, you're famous then."
They'd be amazed that you have proof that you come from the future, because of the camera and cell phone.
Wouldn't that be cool.