The always-clean workbench
This sheet metal workbench cover is the first upgrade I made to my garage, and it's one of the wisest investments I've ever made. (Well, it beats my two wedding licenses anyway.) It's easy to clean (just squeegee the oil into the gutter and drain bucket), and it's heavy duty enough to handle heavy car parts. All it takes is some measuring and sketching and a trip to a sheet metal shop or a local HVAC shop and steel yard. The whole thing assembles in less than an hour and costs less than $300. Skip the steel decking if you wish, but it does prevent the top from denting and provides a more solid work surface. I paid $180 for the top and $92 for the 11-gauge (1/8-in.) steel plate (cut to size and then whacked into thirds for easy transport).
Jack and jack-stand holder
Haven't you tripped over your jack stands enough? Build this brain-dead–simple storage rack and get them off the floor. If you have a lightweight floor jack, add mounting hooks under the holder. Screw a 2-in. PVC coupler onto the side of the rack and a 2-in. cap on the wall near the floor for the handle.
Grease gun holster
A grease gun is big and, uh, greasy. So don't slime up your drawers or cabinets with it. Slice up a few sections of 1-in. and 3-in. PVC pipe and screw them to a plywood backer to make this slick grease gun holder. Then slap up a 2-in. coupler and cap to hold a backup tube of grease.
PVC drawer organizers
When you're right in the middle of a project, you don't need to waste time pawing through drawers looking for tools. So keep frequently used tools neatly stacked in your workbench drawer using this handy setup. Cut 1- or 2-in. PVC pipe to length. Glue on end caps and then slit each pipe in half on a band saw. Screw them to the drawer bottoms and load them up!
Central vacuum for the garage
OK, I admit it. This setup is overkill. But once I got the vacuum mounted to the wall, it just made sense to run inexpensive 2-in. PVC all over the place. That way I didn't have to drag the 35-ft. hose all over the garage. Buy adapters to connect standard plumbing PVC to the vacuum (central vacuum fittings are 2-in. O.D., while plumbing fittings are 2-in. I.D.).