Ok, so Mona g are planning on adding pistons. In the mod it is based off, a piston can be constructed with gold to make a sticky piston (one that pulls stuff as it retracts). Yes, this does create another use for gold, but isn't it time slime balls got a use? Perhaps sticky pistons could use slime balls in the recipe
See Piston Pullers in my sig. it covers both Sticky and Magnetised Pistons
The update is based off a mod which has sticky pistons using gold.