Quoting Russ Abbott, from the post of Mon, 11 Jul:
Hi, As a new wiki user, I have what may be a trivial question. Is there any way to set things up so that users can elect to be notified when selected pages change?
not with the plain-vanilla MediaWiki, sadly, but there's an excellent extension of it, and it is kept closely up-to-date with the main product:
http://sourceforge.net/projects/enotifwiki/