Ask HN: Companies that provide a hosted wiki?

[slackerIII]

I need to organize a bunch of information with some family members. I would like a wiki that: -is hosted by someone else -supports accounts (ie, is not publicly accessible) -makes it relatively easy to export all the content so I can back it up

I'm happy to pay for this, particularly if it means the company will still be around in a few years.

Does any one have any recommendations for a company that provides this? If a YC company has done something like this, I'd be happy to give them a shot.

[noodle]

http://pbwiki.com

its undergone some changes lately, but try the free version to see if its something you'd like. i forget if privacy features are free or if you have to pay

[stuff4ben]

Google Sites might fit your needs, although I'm not sure about the export feature you require.