On my trek back from California, I stopped to use the restroom in a McDonald's in St. George and was shocked to find that the restaurant was using Emeco's Navy Chair! With a price tag per chair of $415 and up, you can probably understand my surprise. To me, Emeco is a high class kinda design company, not one I would expect to have fast food restaurants using their chairs.
The original navy chair was designed for navy ships in WWII and could supposedly withstand a torpedo blast. Check out some fun videos of people 'testing' the strength of this chair by dropping it from a 6 story building, catapulting it and even shooting it with a rifle!
Here are some other discussions I found about McDonald's using modern designer chairs (and even some talk about them being knock-offs *gasp*)!
Egg Chair at a MD's in Europe.
NYC McDonald's gets a modern make-over.
A flickr group of Emeco chairs found on the streets.