Well, I never knew that. Wiki means fast or quick. I thought it meant that it was a small off-shoot of Wikipedia, until today.
Anyway, now I know that it is a type of do-it-yourself web page, I can immediately think of a good use that it might be put to. In our department, we have several visiting scholars working with us every year and we basically have to provide the same information for each. I think this information could be collected together and made into a Wiki so that any visiting scholar could refer to it before, during and after the visit. The beauty of it being that with each scholar's visit and experiences the Wiki can be updated to hold the current and most useful information by the very people who use it, the experience of the user always being richer than the onlooker.
I had a browse round several of the Wikis recommended and thought that other libraries used them very well to induct and train new staff into best and common practice for that library or department. No reason that could not be done here too.