Anyway, I'm really kicking myself for not getting into this sooner - I only started doing it partway through my last vacation - because it means I missed stuff like this all the times I've ridden the Yamanote line in Tokyo...

I sense some serious train-hopping on my next trip.
Curious to see if we had something like this in the US I did some googling. Turns out the National Park service has commemorative stamps. Yay! Umm...What do they look like?

Ummm...ok. Think I'll save up for plane tickets instead.
Blogger Danny Choo has a great post explaining stamps in Japan. The top image in this post is from his Flickr photostream.