So, now's the time to dust off Google Maps! (For a Google Earth-friendly KML file, click on the link and choose the option on the upper right corner.) The interactive map has most of the places I visited, along with some bars, restaurants, and hotels. There are some short notes in there that may or may not have made it into the blog, so check it out.
Farthest Location West: Le Château de Versailles, Ile-de-France, France
Farthest Location East: Bistra, Maramures, Romania
Approximate West-East Distance: 1000 miles/1600 kilometers
Farthest Location North: Köln, Nordrhein-Westfalen, Germany
Farthest Location South: Padova, Veneto, Italy
Approximate North-South Distance: 440 miles/715 kilometers
Since I actually made a big circle, the travel in Europe distance is more like ≈2350 miles/3780 kilometers. If you add in starting at Newark and ending in Pittsburgh, we're talking 10,000 miles/16,000 kilometers. Also, remember that these distances are approximate because they're as the crow flies and assuming that the Earth is a perfect sphere (it's not, actually) with a radius of 3963.1 miles.