HN: Help me choose a Clojure project

I'm looking to learn more about Clojure and, of course, the best way to learn is to do. I'd like to do a small project, maybe around 4 to 6 weeks total, and I'm sure I could come up with something, but I thought I'd throw it open to HN and see what others might suggest, to get to know some of Clojures strengths and weaknesses. Whatever I end up doing I'll blog about and release as OSS, hopefully providing something back to the community.

Suggest away.