I did a fancy Shutterfly photo book of all my ballpark trips (scanned tickets, programs, photos, etc). Really excited to see it (although it was pricey - but so was going to all 30 stadiums). I added an index of all my road games at the end (thanks retrosheet). 50% off all photo books right now.
I also discovered a missing Cubs game I didn't have - Sept 12, 1998 - Cubs 15, Brewers 12. How did I not remember THAT one?

I vaguely recall a foul ball hit by Mark Loretta landing in the lap of the lady next to us... but the game? nope. But I found the ticket stub (I wish I had kept more ticket stubs, or at least organized the ones I did have).