I've got some of the interlocking tile things, got them from Sumitt at a very reasonable price....they sure don't like welding sparks, though!!! I have the ones that are about 1/2" thick, I position them around what I'm working on to make the wear and tear on the back and legs a bit less then plain old concrete!!!

For the floor itself, I clean everything out and scrub the floor once a year and apply another coat of the $20.00 a gallon implement enamel with a hardener. It holds up quite well and is certainly an inexpensive method of keeping the floor looking decent...