This is one of those awesome ideas that I am kicking myself for not thinking of. Basically you're challenged to come up with 30 characters in 30 days. They can be any genre, and any type. It lasts for the whole month of November; you sign up for free, and commit to posting your creations on their site. If you're a writer, you can come up with a character description or bio, or maybe a short scene that describes them. If you're an illustrator, you can draw your own or you could use HeroMachine to create yours.
It sounds like a fun way to stretch your creative muscles and challenge yourself. Apparently only 100 people have completed it, which sounds like the gauntlet has been thrown! If you're of a mind, head on over and check it out.