Thanks both Unregister but I've the same concern with Phill104.
Actually I've already set up a WikiMedia server for experimental on our Intranet server. It's very easy to setup, to add/modify/delete a page/image is also very easy.
Anyway I think to keep it free of spam and clean from the junk information wouldn't be simple. I've heard that WikiPedia has dedicated lots of man power and budget to keep their server clean.
Perhaps we'll setup one when we're more ready but not now.