Gizmodo pointed me this morning to an oh-so-wrong yet oh-so-fun Google Maps mashup, that allows you to nuke the city of your choice. Simply search for your favorite (or least-favorite) city, select your weapon, and nuke it! It was interesting to compare the blast radius of the Little Man and the more modern nuclear weapons. Suffice it to say that today's weapons are awfully scary.
My favorite, however, is the asteroid impact. Most. Destruction. Ever.