Have you heard of Pocket Letters? It is the latest thing for snail mail and pen pals. You purchase the trading card pocket sheet protectors and fill each pocket with some goodies. If you're interested in swapping with other 'Pocket Pals' you can join the group at www.pocketletterpals.com !!
I'm not sure why my picture is sideways! It doesn't look like that in my files. Anyway, you get the idea!