Hello,

  MindTouch has a hosted wiki service based off of our product Deki Wiki.  It is Free to use and includes the ability to have private wikis.  There are no ads and we include tagging of pages that can be aggregated on a page so you can easily build a page that shows all of the orphaned pages.  For only $99/year you can upgrade to Pro which gives you 10 gigs of space, the ability to add a custom url, and custom HTML areas for scripts and ads if desired. 

You can sign up for your wiki here: http://wik.is

In regards to creating a page with the orphaned pages on them, you would tag the pages you consider as orphaned and then you would be able to aggregate those pages by entering the following script in the editor on the page that you want the pages to appear:

{{wiki.search("your_tag_for Orphan_Pages")}}

This will display a list of all of the orphaned pages with the tag you associate with them, like orphaned. 

In regards to to surfing to a random page, you can set it up so that a random page will appear on any page.  This uses a similar syntax as above but you can chnage how often it will present a new page.

  {{wiki.anypage("the search term")}}

These functionality are just scratching the surface of how robust Deki Wiki is. I recommend you watch our demos on this page to learn more about the functionality of Deki Wiki: http://wiki.mindtouch.com/Deki_wiki/Demo

Vincent,

  It would be great if you could post these questions in our community forums here: http://forums.opengarden.org so that the whole community can benefit from it.  I don't know if I mentioned it, but Deki Wiki is open source and we like sharing information with our community. 

Thanks