Stick Propeller
Propels you 5 blocks upwards when used on the ground or in water.
Nice and cheap way to gain some height!
Consumed on use.
It stacks up to 16.
Recipe
7 sticks like this. (Gaps in bottom middle and left middle slots)
Trivia
This idea came to mind while we were playing Split Fiction. Near the end there's something similar to this item!