Sorry, "Pappy". Sorry, Joss.
Wikipedia has become the true master of my universe. It has become incredibly useful (to the point of indispensable) as a quick-research tool while I am working on adventures, campaigns, settings, and anything else to do with gaming.
To wit, the current adventure I am crafting for a client (via the Your SAVAGE Expert thing I've got going).
My instructions included starting the adventure in Fargo, North Dakota.
The year is 1893.
The ultimate destination is the Chicago World's Fair.
There's some stuff to do with Tesla.
For added veracity, since there was a train ride clearly necessary to the event, I ended up looking into Chicago's Grand Central Station and the train rails the group would likely end up on, the Chicago Great Western Railway.
In reading over information about the Fair, I realized Buffalo Bill's Wild West Show was there (though not an official part of the Fair); this led me to realize I could work in such luminaries as Annie Oakley and her husband, Frank Butler, into the story.
All this history and verisimilitude would have taken literal hours to accomplish, either by poring through a set of home encyclopedias or via a trip to the local library, when I first got into this business. Granted, anyone doing serious research should still do that kind of thing, but for gaming, Wikipedia is just... amazing!
Naturally, I donate to it semi-regularly. It's worth far more than I give, that's for sure.