An adapted design of flyingferret's :
This thing allows for real quick and precise adjustment of the Z limit switch.
The Leg screws into the X stepper through the X carriage and the slotted holes provide for larger adjustment where an M3 bolt/screw then allows for fine adjustment.
I used a thread tap to cut straight into the plastic, i'm sure a normal screw would cut its own thread in there easy enough if you apply enough force. Same applies to the little foot that screws onto the tip of the M3 bolt. The limit switch screws onto the switch mount with 2x M2 screws (which came with my printer)