Just spotted on Lifehacker.com is this announcement of an extension from Sun Microsystems that allows you to edit a MediaWiki page from within OpenOffice. MediaWiki is one of the most powerful wiki tools available (it powers Wikipedia) but it also has the most complex syntax. Because it works like a word processor, the Sun Wiki Publisher extension may be just what you need to exploit a Mediawiki installation with minimum pain.
Update: I just intalled OpenOffice and the Sun Wiki Publisher (itself a challenge on Vista!) and gave the wiki publisher a whirl. A serious issue is that though it will write a document created in OpenOffice Writer as a new page in a MediaWiki wiki, you can’t open a MediaWiki page for editing. This means that the tool has a write once feature and thereafter you presumably maintain the page in MediaWiki markup through a browser. Even so, it may still prove to be useful in getting a lot of content into a wiki (perhaps even from content that is imported from MS Word) and for this reason alone it is probably worth a longer evaluation. Perhaps the developers are working on round-tripping for the next version.
OpenOffice, MediaWiki and the Sun Wiki Publisher extension are all free (as in beer and as in speech) and open source.
This looks very interesting especially given that a lot of people start in a word processor and paste into wikis and then get all the formatting gink that Word adds.