Billed as a "reference tool for members of the Prairie Area Library System", this is a good example of a wiki being used as an "internal" document.

While many of the pages still need to be fleshed out, there are useful guides to databases and newspapers by location. This can sure come in handy.

There's also a Reference Answer File which leads with the question, "Where do babies come from?" This also contains links to "Answer Files" from other sources.