Simple Steam Engine —- air powered
This is a simple steam engine running on air blown through a drinking straw. The design is very old but is easy to build with basic tools and average skills. A link to the plans are below.
I show it here powering an electrostatic generator which in turn powers an electrostatic motor.
https://docs.google.com/file/d/0B1Bu7fj2LMPna0xDZWdhS1hNaEk/edit?usp=sharing