Challenge Accepted - Redstone creations

This map file is what I hope will only be the beginning of my Challenge Accepted - Redstone Creations. I put a blog up today asking for a redstone device challenge, and I was sent a piston elevator as a challenge. Having completed the first challenge, I ask that anyone who is reading this challenge me to build a redstone device. You can see more info here : http://www.planetminecraft.com/blog/redstone--challenge-accepted/

Additional Notes

Please give me more suggestions so I can turn this into a series, this is only a piston elevator now but with enough suggestions it may become a collection of functioning redstone devices that can be used as references to making your own.