Being that my inner child never stops wondering "how it works", I was looking at my 160 degree t-stat from LMS wondering how it actually worked. I decided to search "on the line" and found this pretty cool video showing the thermostat at work. I watched this with no audio, so, I have no clue what he is saying but the demo was pretty cool! Fast forward to 0:30 to see the stat actuating.
http://www.youtube.com/watch?v=T8cGKdICJmc#wsFrom How It Works:
"The secret of the thermostat lies in the small cylinder located on the engine-side of the device. This cylinder is filled with a wax that begins to melt at perhaps 180 degrees F (different thermostats open at different temperatures, but 180 F/82 C is a common temperature). A rod connected to the valve presses into this wax. When the wax melts, it expands significantly and pushes the rod out of the cylinder, opening the valve. If you have read How Thermometers Work and done the experiment with the bottle and the straw, you have seen the same process in action. The wax happens to expand a good bit more because it is changing from a solid to a liquid in addition to expanding from the heat."
Cool Eh?