In Montana, there is a town called Haugan on I-90 near the Idaho border with an interesting building. As you approach, you see signs like this every couple of miles. [click on the pictures for a higher res image]
Outside, the place looks like any tourist trap.
Do they really have 50,000 silver dollars inside?
And at the back of the bar they have a sign saying what the current count is. I visited twice, 1 year apart.
In July 2010, it looked like this: In July 2011, it looked like this:
[Please leave me some challenging questions in the comments. I am looking to develop this into a classroom material lesson. I also have more pictures of the inside, I just posted a few of them here.]