Like zamboniracer, my only experience with foul balls are from Municipal Stadium. When I was a kid we’d go to games and my dad was a young buck and he’d run down the stands and pick up strays. I think we got at least 2, maybe more.
Sad story:
For the past 3 seasons, I’ve been getting to use a client’s sweet 4-pack of season tickets from time to time. I always take my 2 best friends with me and maybe a date if I’m seeing anyone.
I really love these seats. They’re 5 rows up, just past the Indians’ dugout and camera bay. If I get the tickets and can’t get people to come with (not easy to find Indians fans these days), I go alone.
So, I went to the last home game of the season a couple weeks ago, alone. I sat myself in seat 1 of the row. Seat 2 was for my sweatshirt. Seats 3 and 4, for which I held the tickets, were occupied by a couple of teenagers who wanted to sit in front of the people they were with instead of next to them. Whatever, they weren’t bothering me.
For the first time in about 15 games I’ve had these seats, a foul ball came right to my section. Seat 4. Where someone else was sitting 
The kid caught it on the fly, and the usher took his name and address. I guess if you catch one on the fly they send you a certificate.
To add insult to injury…To show some fan appreciation, all of the players had signed a dozen balls and came out after the game to throw those balls into the stands. I rushed up to the dugout, along with my teenage seat-mates. One of the players rolled a ball right to the kid who’d caught the foul ball.
Then, Chris Perez threw a ball behind me, where my seat was, where I had been sitting before I went up to the dugout. The mom of the kid who now had a foul ball and a signed ball caught MY ball.
grumble