You can never have enough clamps around the shop. Where to store them is another matter, however. Here are three simple ideas:
Buy screw-on pipe caps to fit the diameter of the pipe, then drill a small hole, attach an eye bolt and nuts and screw on the cap. Then hang ’em from a hook or nail.
Or make a simple rack out of scrap wood. Cut the top edge at a 3-degree bevel to keep the pipe clamps from slipping off the rack.
Or buy these spring grip organizers, available at home centers, then screw them to a board. Position the board just high enough to hold the pipe near the crank end while the other end rests on the floor.