Going through my program collection from around the world, I found many interesting things people wrote. I have programs from Jakarta, Indonesia, Macau Jai-Alai, Uruguay, Chile and New Orleans (which was purchased at an antique shop in that area). In those various programs, I saw grocery lists, love notes, scores, phone #'s, vacation plans, you name it! Very historical stuff because these are old programs.
I save all my programs except for the crappy ones from Ocala and other xerox jobs. Not worth collecting. I am making a small museum with my best programs and photos and the notes written inside of them are pretty weird from time to time.