Hey David, thanks for the idea!
I've thought about stickers and even nice Mustache shirts. My main hesitation is the idea that I don't want to cause a factory to pour more unnecessary stuff into the world in the name of this anti-consumer blog.
However, stickers are pretty small, and with the right logo it could be a cool way to allow us to show membership in this elite society. Ideally, I would set them up at a store that does "drop shipping", meaning I would not be licking envelopes and writing addresses all day to distribute them.
Or maybe I could order the big batch of stickers and hire an underemployed Mustachian to handle this duty, keeping the profits within the MMM reader family while creating a job that might pay $20/hour or so ;-)