If I want specific information on a subject I use Wiki. It's just to fast and reliable. On the other hand, when I'm looking for odd torrents (that I can't find on The Pirate Bay) or I'm looking for a specific website for it's utility I use google. Google is nicer if you want to have a broad spectrum of things relating to the subject at hand or you need to find a service on the net. Whereas Wiki is better for information on a specific subject.

As for Slip's comment about wiki making books, I just don't think they will ever make any. First off they just have far too much information to put into books. Second, why would they ever want to put it into books? It's much easier for a student to just search online for the subject as opposed to sorting through hundreds of books. And third, Wiki is great because it is always changing. Books would set it in stone and would be outdated within a month.

I hope that all makes sense.