Familiar with ErdosNumbers?
How many clicks does it take to cross Wiki? Starting from WelcomeVisitors one can get to any of these pages, and lots more like them, in the specified number of clicks. Of course adding this page probably changes the statistics, but we will neglect that for the moment, though it pains us. (Data from May 23, 2001- minor edit anon Aug 5 2004 )
WikiBrowseGame has a LikeChanges? version of this:
Choose two WikiPages.
Go to one.
Click LikePages.
Find the shortest number of LikePages needed to find the other.