Frequent MMSA swapper (and featured artist) Leslie, wants to start a round robin art journal.
(If you're not familiar with the concept: Everyone in the group starts her own art journal and then passes it to the next person in the group. Eventually you get your own book back and everyone in the group has added to it.)
Anyone who is interested can email her directly for the details.
maugreall AT gmail DOT com
Jessica Brogan hosts a wonderful altered card swap on a regular basis.
(formerly known as the "inspiration deck" swap)
You alter an entire deck of cards, mail them to her, and you get back 52 different cards from people all over the world.
I've done it twice and it's amazing.
Here's the website with all the details.