Ever heard of "correspondence art"?

I came across an art term I had never before; never even considered that such a thing could exist: correspondence art. Correspondence art, also called mail art, is the concept of sending small pieces of art through the mail service. Materials used are typically postcards, rubber stamps, collaged pieces of paper or other recycled materials -- or pretty much any kind of material turned into art that can be put in or on an envelope or postcard and mailed off.There are networks of people who love to send and receive mail art. Naturally there are websites devoted to this. I haven't joined an internet group, but I did find a group in San Francisco of mail artists and letter writers and will go to a meeting at the SF main library in a few weeks. How fun it would be to chat with others who love the USPS and make small pieces of envelope-sized art. Here's my first piece of mail art from one of the members. It's awesome!Separately, I joined a post card swap called Postcrossing. I completed 5 post cards and mailed them to 5 different countries (they sent me the names and addresses). Once they receive my post cards they log it with the website through a code I write on the card, and then I will receive 5 postcards from 5 other individuals. I think it sounds kind of cool. Mostly I'm looking to see what kind of stamps and images on the postcards I get. I want the kids to see what comes too. Here are a few I did (don't mind the stars. That's just to cover the address and bits):Anyway, I've begun thinking about envelope art in a new way and that's intriguing to me.