I've found that tweezers are the only tool that I use all the time with the RepRap (to remove crud from the nozzle) and I can never find them. This clamps onto one of the frame rods of the RepRap to keep your tweezers handy. Note that it was designed for 3/8" rod, though it should fit the metric rods if you put a piece of tape around them first to make them slightly larger.
Print out the pieces. Clamp onto RepRap. It has through holes that will accept coarse threaded screws or you could use machine screws with nuts.