I was also looking for some space saving ideas in the shop/garage. I built a stand that has a 20" x 20" platform. Then I took a few 24" x 24" pieces of plywood, and added some cleats of the bottom to fit them securely over the platform on the stand. I mounted my grinder, small router table, and a belt sander to the plywood sheets. Then whichever tool I need, I pull off of the shelf and set it on the platform. It works pretty well, and the lack of horizontal space prevents me from leaving my tools out all over the place.