This is something I wanted to try to enable announcements and discussion for things going on at javabat.com.
So after just tons of coding, the often requested feature of editing your own problems now works, see the authoring docs and the javabat authoring page (you need to be logged in to do anything).
You can create little pages of favorite problems, and with more effort you can create your own custom problems. I'm still working out how to integrate the custom problems with the main site content. Anyway, I'm quite curious to see how it works and what direction to take it.