I actually own mound dirt from George Brett Nolan Ryan's last game in uniform (also the last game at old Arlington Stadium) in 1993. I pocketed this dirt myself on Oct. 1, 1993.
I also have Anaheim Stadium dirt obtained from game 7 in the 2002 World Series in which the Angels finally won the World Series.
Finally, I have stadium dirt from old Tigers Stadium from Sept. 27, 1999 (last game at "The Corner"). I swapped a friend for some of my Ryan mound dirt.
Silly, but fun!