For the life of me I can't see why someone who can't figure out how to use (not install) the Manuals module should be writing documentation anyway. But, at least on my instance of the module, linked to above, comments can be added at the bottom of the page.
Here is an Idea: download the current aolserver documentation. Run general comments on top of this and then users can add examples and comments on a per function basis. That only covers the AOLserver API, but it is a start. Or we could load the Manuals module with this info, and it looks like htmldoc would create the pdf files needed for a hardcopy. You can still run comments off these pages and collect the good examples into the docs from time to time.
But freeform editing isn't going to help anyone find anything. Tiny sub-sites popping up from time to time under the openacs banner also isn't going to help organize or enlighten. What might help is dumping the database contents into the filesystem into a search bot friendly url (http://openacs.org/bboard/11/00025d/message.html) and submitting these links to AltaVista.
If you doubt this works very well, consider saleonall.com. I submit one link every 6 seconds to AltaVista. Currently there are over 85,000 links from that site available on AV. Pick your favorite obscure manufacturer part number, type it in and more than likely several of the first page links will be from saleonall.com.
The bboard could be altered to allow the inclusion of a keyword or keywords for the particular message. When the messages are written out to disk, the page title should start with this word or words.