Addon that let's any users make edits to a post, or 'wiki-like' section of a thread?

[Tomeeboy]

There may be something like this already, but I'm looking for an addon that will allow me to toggle a 'community editable' option on a thread. Basically, this would allow members to make edits to the original post in a thread, or possible some kind of sandbox section below the main post.

It would be a great feature for informational threads that may require frequent updates, or long threads that have key pieces of info hidden throughout many pages (as they could be summarized in the editable area of the thread on page one).

Anything like this available, or in the works? I don't want to turn my forums into some kind of disorganized wiki knock-off, but would like some minimal wiki-like features that can be enabled on specific threads when needed.