I had an idea for a magnetic block powered by redstone.
The concept is similar to that of a railgun. The idea is you could make a line/path of magno-blocks and then place iron blocks on top of the magno-blocks. By powering the magno-blocks with redstone, it would then cause the iron blocks on the magno-blocks to travel down the path (along with anything sitting on the iron block). When the power is shut off, movement of the iron blocks stop.
Magno-blocks could be used to make elevators, mass transport, draw bridges, portcullis, Star Trek doors, or any manner of devices that regular pistons couldn't handle.
Suggested recipe for a magno-block could be a block of iron or an iron bar surrounded by a ring of redstone:
In addition, it think it would also be neat if the magno blocks showed power going through them in the direction the line moves the blocks, something like: