I got bored one day and thought I would try making a Triple Piston Extender which I hads never done before. It was actually very easy but just getting it so each piston extends and retracts at just the right time for jsut the right amount of time was a pain. Still it was very easy. Anyways download this thing at your own risk because I remind you it is VERY slow. 

Thanks for checking this out. :)