Since it appears nobody got hurt, I feel OK saying that was pretty cool. I've never been through an earthquake before, and it was 5.9 so it wasn't unsubstantial either I guess. The walls were definitely shaking, and they evacuated us from the building for a while.
The epicenter was just a couple miles away from where my sister-in-law used to live in central Virginia, which was interesting.
I liked the response that my sister shared on facebook that is pretty typical in D.C. - first thought: "was it terrorists?*", second thought: "damn construction!".
Anyway, apparently there was a decent sized earthquake in Colorado too. I think, rather than do some googling to see how common this is, the only safe thing to conclude is that this is a consequence of the galactic alignment :)
UPDATE: Wow - and the Cafe Hayek comment section on Russ's earthquake post is talking about... you guessed it!... Paul Krugman. This moving into elementary school boys punching girls that they like territory.
* - As problematic as acting irrationally on concerns about terrorism is, you definitely think about it more around here, and probably not without cause.