Billy Hamilton chased down a fly ball in the gap then turned it into a one of a kind souvenir.  After making the running catch, he climbed the wall and let a kid take the ball out of his glove.

The kid went to the game thinking he was going to get a souvenir, but he probably thought it was going to be a home run.  Instead he had a major leaguer bring him a ball.  

What a move by Billy.  The MLB needs more of this kind of fan interaction.  It’s the best.