WikiPublisher is an add-on to PmWiki that will neatly typeset collections of pages using LaTeX, and serve these up to a user in PDF form. It's available as free software in two packages: the PmWiki addon that causes PmWiki to generate appropriate XML, and the typesetting server, which transforms this XML into PDF format.
Available at http://www.wikipublisher.org/
Very nice! I don't care for PDF format personally, but very nice all the same.