I was poking around in my parents' basement while home for Christmas, and found this postcard:
It caught my eye because it looked familiar. Not the postcard itself, but the view, from Glacier National Park. In fact, I took almost the exact same picture on my own trip to Glacier this past September:
The postcard was from my paternal grandparents, sent in September 1984 -- almost exactly 27 years before I inadvertently took the same picture.
I must admit that Doug is right -- there's something special about physical postcards, compared to all the different flavors of instantaneous electronic communication. If I had run across an old email, it wouldn't have been quite the same, never mind that emails won't just hang out in a box for a few decades to be stumbled upon later.