In an earlier post about wikipedia, I wrote about how I like to check out comic book titles that I am unfamiliar with before I buy them. You can get rundowns of the plots of a whole series.
Another nifty thing I like about Wikipedia is that you can use it to find time lines. This is often handy when kids are doing school reports. For instance: "I have to do a report about something that happened in 1969." If you type a year, like 1942, into the Wikipedia search bar, you'll get an article about that year with events listed by month, lists of births, deaths, and events by other categories, I'm assuming as strikes the fancies of contributors.
In addition, there's a funky panel on the side that will lead you to macro and micro-topics: 1942 in New Zeland, in Art, in whatever. What a beautiful browsing tool.