Check out the Sketchbook Project, Volume 3, over at Art House. Art House aims to build art projects and communities. For this project, they send you a small sketchbook, which you fill and send back to them. They then take the sketchbooks on a 6 city gallery/museum tour. The theme is "Everyone we know".
It costs $18 to participate, which isn't too bad. And if you send a self addressed stamped envelope, they'll send you back your sketchbook.
Their previous skecthbook projects got press in magazines like Good, Juxtapose, and Readymade.
The deadline to send in your completed sketchbook is Feb. 15 2009, so if you sign up now, you'll have plenty of time!
Check out some of their other projects here.