A couple of people have asked me for ideas on this, so here are a couple of ideas:
i) A Thousand and One Nights. For this you have to make, and/or mail, a piece of Mail Art for, yes, you guessed it, 1001 nights.
ii) 20,000 pieces of Mail Art from Under the Sea: A Tribute to Jules Verne. Now this will not only keep y'all very busy, but also might lead to the start of the very first Underwater Mail Art Exhibition. In addition, it will set some challenges, -- such as getting the glue to stick when it's all wet, making sure that the paint (and your eye make-up) doesn't run, fixing the stamps to the envelopes, etc.
I hope that either or both of these appeal to you.
Liberté, Egalité et Art Postal Forever!
"300"...made in Sparta, Greece?
Or you can do a Dewi and bring on 1000!
Another challenge could be to keep making mailart until Andy finishes, which may take longer than 20,000 pieces of mailart from under the sea at the rate I'm going
How about 101 Dalmations... white on black or black on white spots, splotches, dallops, glops....etc....