From Authentication Tools for Joomla! (JAuthTools)
The wiki is set up to not allow anonymous edits or sign ups. The reason for this is simple: the contribution audience for this wiki is limited and I don't want to manage yet another source of spam or defacement.
However if you want to add/edit/update information on the wiki, I'm more than willing to create an account. Either create a todo on the project tracker on Joomla!Code or find an email address and mail me and I will be happy to create an account for you to do as you wish.