From: "Mohamed Magdy" mohamed.m.k@gmail.com Subject: [Wikitech-l] Who is online?
Is it possible to have such a feature on Wikimedia wikis? or it will not be accurate and have the same problem of page views?
Try http://www.mediawiki.org/wiki/Extension:CurrentUsers
I have not looked at it personally, so can't vouch for it, but it claims to do what you want.
- Mark Clements (HappyDog)