I have used the usual interlocking floor mats off and on for several years, but I hate them for various reasons. They are not the most steadfast surface for hand tool work in that if I am planing something they will slip and slide all over the place. They are a bear to clean dust and shavings off, and provide a very minimal protection to tools falling off (which almost never happens in my case -knock on wood- so that is not a big concern).
Just curious as to what others are doing to avoid standing on a concrete floor for extended periods when working on a project.