I have a few, nothing old though. Probably the most meaningful is the coin from my college AFROTC unit. The story behind it: freshman year, I "donated" $100 to 1) get a discount on dining out tickets 2) get a t shirt 3) get a challenge coin. Ironically, besides a $10 discount on the tickets nobody got the Tshirt or challenge coin. It wasn't until a full 4 years later, when I was in grad school, that a friend of mine managed to pull some strings (somehow) and get me the challenge coin I was owed from years ago.