I'd gladly sell you a calendar of Zuni pictures! Perhaps you're on to something though. Our themed threads (Pets, Landscapes, Nature), and even our assignments are all potential calendar making material. I'm not sure how you can get them printed somewhere reputable, and still be cheap enough to sell a boatload of them though.

I ordered calendars from Vistaprint once, and they were quite nice, but not as cheap as you'd find in the mall stalls. The mall stalls don't get made somewhere reputable though. One year our calendar had a week in August where ever day was labeled Tuesday (true, I swear!), and the year before that there was something else screwed up, like 3 Wednesdays in a row.