Quirky little souvenir

Whenever I leave the country and I'm sending some postcards back home, I always throw in one for myself. It makes a cool little souvenir. You're reminded of how much fun you were having when you wrote it, and you get a stamp and postmark from the country you visited, all for the price of a postcard and stamp.

I think one of the aunts first suggested this to me in Italy, but I can't remember which. Any takers for this good idea?