So I recently found out about this whole "geocaching" thing. Apparently it's a hobby lots of people have where they'll bury something (or just put it in a container, hidden) somewhere around you, and send you out on a hunt to find it. I know, it sounds a little childish and corny, but
what else is there to do in the Centreville area?
Anyhow, it turns out that these people leave all kinds of weird random goodies for people to find, along with a log book for you to sign saying you've been there, and you can leave something in return.
At first, they told me I'd need a GPS finder to find half this stuff. Truth is, all you really need is Google Earth (free) on your pc, or go to maps.google.com (free). Type in the coordinates, follow the clue, and bam, you found the cache.
Oh, and there's like
3,000 matches for the Centreville area.
http://www.geocaching.com/local/default.aspx?state_id=47&x=9&y=7