Hidden Pop-up Staircase[]
Vertical Power Transfer via Pistons[]
Basic idea came as a solution to someone's problem for compact vertical power. Proof of Concept on YouTube
Block Detector[]
Device used to check if the block in the 'test zone' is conductive or not.
redstone torch -> redstone wire -> 'test zone' -> repeater
Gravity (Up Only)[]
A stack of gravity-affected blocks on top of a regular piston facing upwards. Very top has a block-detector for output. Best use of gravel I've found yet :P
Quick to activate, but slow to reset. The taller the stack, the more time needed for everything to settle back without 'erasing' blocks.
Gravity Repeater[]
Extends the length past the 12 block limit of a piston.
Solid (Up or Down)[]
A stack of solid blocks. Stack is pushed in direction you want power transferred and is pushed back by the receiving end at a delay.
Quick to turn on and off, but tends to get stuck if set to too short a delay or triggering side stays active too long. Additional bonus is power can be checked midway without need of extra circuitry besides a block detector, just use a non-conducting block in the stack where you check.
Bi-directional Bi-stable[]
Two stacks, need not be in direct parallel, that when one stack is 'on' the other turns 'off'. This will allow it to be activated from either top or bottom.