We each have some place we started out as kids. No matter where we go, this will always be the CenterOfTheEarth.
"Anybody ever try to draw all the routes you know you have taken on a map? The result, for most travellers, is a spidery network of crisscrossing travails. The CenterOfTheEarth would probably be the area where the lines on the map were most frequent (I hesitate to say 'darkest' because I've done this on my map with a yellow highlighter.
Of course the Uber-geeks have already made a GPS interface which can do the mapping for you, and the ThreeLetterAgencies are hard at work in creating a chip that can be placed in your head that will do the same thing." -- SeanOleary, wearing TinFoilHat
Speaking of which, despite the BigBrother overtones, I always thought it would be useful to Lowjack my boss so I could always find him.
Update: MarPlot is free (as in beer) GIS software provided by the US EPA and the US Census Bureau. It's not exactly ArcInfo?, but it it free. It's also a very good way to plot the CenterOfTheEarth.