Zack Hample, an obsessive baseball fan, has by his own count snagged 3,123 baseballs at 42 different major league stadiums. And he's turned his obsession with the game into a career, giving tours of stadiums, appearing on TV and radio and writing books — including Watching Baseball Smarter: A Professional Fan's Guide for Beginners, Semi-Experts, and Deeply Serious Geeks.