This is a Flash game that asks you to place each of the states on a map. My average error was 14 miles. (Hint: look at the rivers.)
If you put a state in the right location, it disappears — which means it’s not visible to help you place the next state. If you get a state wrong, the outline appears on the map in red. So if you’re good, the game won’t get easier as you continue. If you make a lot of mistakes, the game will get easier.
Via Metafilter (which has links to some other country maps, too.)