Ok, so I’ve been quite slack in completing the Spark plugin which was going to be the be-all-and-end-all of super duper crowdsourcing needs. I’m still planning to complete it <one day>.
That said, I have submitted an application to host my new Table of Contents Plus plugin on the WordPress plugin directory. Once approved, you should be able to install it using the normal process including via the administration backend.
Why Plus? Cause it does more than a table of contents!
In the meantime, you can check out its plugin page which has more information about it, and some screenshots.