Watch as this guy "crashes" cell phone conversations inside airports. He simply walks up to these strangers and begins to engage in a conversation on his phone that seems to be verbatim to the one next to him. 

I could totally see myself doing this, but with all of the new rules and regulations in airports these days, I'd be afraid to try this. You never know how TSA may react, and if its not in your favor you could end up on that "No Fly" list. OK, maybe that is stretching it, but this is still a very entertaining prank.