In many mechanical solution, the flexibility of materials is use as a function. Metal springs are a very common example of this. But almost any material can be loaded with tension and then used as a functional part. Make: magazine made this interesting video on how simple flat wooden sticks like popsicle sticks or tongue depressors can be used as if they where springs and cause a chain reaction. But there is no reason to stop there, almost any material can do the same. For example, we would love to see you make the worlds first spaghetti bomb!
This is a very short but valuable tip from John Heisz on how to use your drill press when the piece you want to drill is too long to fit. It is fascinating how some situations can be solved with the simplest tools and parts. Enjoy!