Is a wiki-style section really necessary for the tech articles section, and would it really be *that* good an idea?
For one thing, well-written tech articles that are decently focused on a particular topic shouldn't need to be edited or revised all that often, which would negate much of the percieved need for a wiki. Static HTML isn't difficult to update when the need arises, and well-written HTML (as opposed to machine-generated spaghetti from FrontPage, Dreamweaver, etc.) can be updated with a simple text-editor.
Secondly, I've visited a few sites that have wiki sections in addition to regular forums, and on most of them the forums have been neglected by the users -- discussion taking place inside the wiki, with the usual edit-wars and other crap that tend to happen. I'm a-feared that adding a wiki to this site may lead to the same thing.
Thirdly. One of the beautiful aspects of a wiki is that just about anyone can edit pages and add new information. One of the downsides of a wiki is that just about anyone can edit pages and add new information. Even if it were set (here) to only accept edits from registered users, there would still need to be a mechanism in place to keep Joe Blowhard Arsehole from making an account and defacing things anyway. Yeah, a page could easily be reverted to the previous version when that sort of thing happens, but it's still a hassle.
Bottom line -- I don't honestly see how a wiki for the tech articles is really needed, at least at this point in time. IMO, the amount of work needed to get the PHP upgraded, get the wiki set up, get the wiki populated with info, and (collectively) babysit the wiki is far greater than whatever benefit a wiki would have.
My $0.02 .. and with as much as I wrote, think what you could get for a dollar!