In order to impress upon Europeans the size of the United States, I've been telling them that the distance between Portland and Boston (the two cities I know best) is about the same as the distance between Brussels and Baghdad. This was based on my estimations while looking at a globe one day. My point was that, when flying from Portland to Boston, you're flying over one country, one culture, one language; while flying from Brussels to Baghdad, on the other hand, you're flying over multiple countries, cultures, and languages.
Well, I just discovered a website that calculates the distance between any two major cities as the crow flies, so I checked it out.
Brussels to Baghdad: 2350 miles (3782 km)
Portland to Boston: 2541 miles (4089 km)
So I've been underestimating it this whole time. I looked for another city to make it more accurate, and came up with this:
Brussels to Tehran: 2542 miles (4092 km)
It kind of freaks me out to know that, right now, I'm as close to Tehran (and closer to Baghdad) than I am to Boston when I'm in Portland. And that's just straight across the States for the most part; if you go from one corner to another (Seattle to Miami, say), it's an even greater distance.