Yesterday I saw a story on KVOA-TV about the new Community Chalkboard. (Actually, @DowntownTucson tweeted about it.) I couldn't wait; I headed straight for the corner of Arizona Avenue and Congress to check it out:
The chalkboard is 40 feet long, and chalk is supplied. Since it's cleaned often, it's like a constantly-evolving mural. Thanks to David Aguirre for another creative downtown art project.