WIKI really reminds me of petting a kitty. It gives you a chance to do something that is appreciated by someone else (sharing information or extending your perceptions). In return you get to review the thoughts and perceptions of others which may assist you in formulating or expanding your own. Both you and the kit benefit!
Their use in libraries could be endless, but I'm going to focus on just one- the youth services and young adult departments.
This would make planning a talent show or producing a play SO much easier. Coordination is instantly updated and new ideas shared immediately. You could publish the script and get feedback from all quarters- then rewrite using the best of the submissions. Planning for sets and costumes would also benefit- more ideas, more suggestions- all of which would make it better.
Follow ticket distribution, promotions- get info to stage hands and lighting people- publish your needs and get a broader response- so much comes to mind! You could run the whole thing- right up to last minute info- without a million phone calls, text messages or emails. Your children's section would be the top cat!