I have finally found a project for learning Common Lisp better. I've been implementing a lisp interface to facebook's REST API. I found some old code at common-lisp.net, which had lots of useful hashing/request forming code, but was using an out of date API and had no documentation.
I'm happy to say it is now much more useable. I applied for hosting on common-lisp.net. So, maybe I'll have a link to that for the interested soon