I had my first attempt at using a Wikki yesterday (bit primitive as yet) However, I was also trying to add some 'help' files on a site , for those (teachers) that are used to finding a help on a main menu (top of the screen) and don't always notice the little ? icon on the Moodle screens ! So ,I opened one of the help windows , clicked on the Index of all help files , did a copy and paste (all of them) and popped it into a Wikki page . Works a treat , all the links go to each topic page , and Help , from one spot ! 
Like this below but the 'links' didn't work in a forum on my site , did in the Wikki ) Fantastic Martin & all you wonderful developer guys ! I honestly hadn't realised just how much information was in behind those little ? Can you stop a Wikki from being edited ?
Joyce 