Thanks to the focused efforts of clever Wikipedians and the WikiProject on Geographical Coordinates there's now tons of geo-tagged entries on Wikipedia.
If you haven't come across it yet, pay attention to the top right of the page when you're searching Wikipedia. If you're lucky, you'll see a little globe following by the latitude and longitude cordinates that relate to the Wikipedia entry.
We're able to do some neat things with this inside of Atlas. We've put together a beta for a new Wikipedia feature. For now you can access it from this URL: http://atlas.freshlogicstudios.com/?Wikipedia
My favorite happens to be the St. Louis example: http://atlas.freshlogicstudios.com/?Wikipedia=St.+Louis,+MO