What's the best way to turn a bunch of email threads into a working project documentation?

This other stack overflow question seems a little stale, but might be the right idea: http://stackoverflow.com/questions/11612/is-there-any-wiki-engine-that-supports-page-creation-by-email

Also, Evernote shared notebooks might be an idea: http://blog.evernote.com/2009/06/25/notebook-sharing-phase-1/

Perhaps there's a good way to convert email threads into HTML or Word docs and save them to a shared dropbox folder?

My ideal solution would be one where I could forward or copy a thread of emails into one spot, and go back after the fact to organize/categorize/add to it.

Any ideas?