How about postcards made from squid?
These Japanese postcards, are made from dried squid (Todarodes Pacificus to be exact) or surume, and are called, appropriately enough, Surumail. You don't actually write on the squid. No, it's packaged into a postcard shape, and then you write your message on a sticker that goes on the outside of the package.
I would dearly love to have one, if only to see the reaction at the local post office when I mailed it. But who would I send it to? After all, dried squid isn't part of the typical American diet. Trying to send one in the States would most likely result in a visit from the Homeland Security folks.
This does lead one to think about what other edible food can be made into a postcard. Dried fruit? Candy? Beef jerky should work well. It's called 'snailmail'–why not escargot?
Better yet, use Spam. There would be a certain poetic irony in using Spam as mail.
(More on Surumail at Pink Tentacle.)
