You know how people spend years at school to learn how to build bridges in America? Turns out a tribe in India has been building bridges with just trees for hundreds of years. All their bridges are made solely out of trees that only get stronger as they grow. Sure, it takes a dozen years or so before they are strong enough for use, but you’re still saving a bunch of money!
Read about the process and more about the tribe at www.treehugger.com.