The Huntsville Concrete Rocket
eric writes: "Students at the University of Alabama in Huntsville have designed and launched the world's first concrete rocket. Video of the launch can be found on their site" Look to the bottom of the page. What's next? Concrete cell phones? I could use a cell phone that could float.
There was a whole article about this in the New Scientist a couple of months ago, it's not on their site but I seem to recall it mentioned concrete planes too...