Once you get used to the idea of a 'free for all' site (hoping that self regulation really does work!) the usefulness of Wikis does become apparent. By drawing on the combined knowledge of many different participants the maximum material is gathered together in one site and is easily added to or updated. Had a good look at the SJCPL site and was impressed by the variety of information available.
I especially like the idea of using wikis for special projects. I was recently involved in one group project which had about a dozen parties with emails being sent all over the place every day giving different suggestions for content, grammar etc. Instead of having to locate these in my Inbox, it would have been so much easier to have everything in the one place that could be edited by each party, i.e. a wiki.