Recommendations for free wiki hosting?

[Spanky Deluxe]

Can anyone make any recommendations for a free wiki hosting farm? There are so many out there that I don't know which to go for. I don't particularly mind adverts being on there, I'd prefer it to have the option to make the wiki private and I'd rather it use the MediaWiki code because I'm used to using it. Wikidot looks like it would be ideal apart from the fact it doesn't use MediaWiki.

[riscy]

I have had a look at http://www.wetpaint.com, and like it a lot - not sure if it is a "farm" as you want.

I have set up several sites there, but do not know idea what MediaWiki is, sorry, I just like the ease of use there.

[timmillwood]

http://www.wikispaces.com/