How do you clean spilled oil off a concrete driveway?

Cat litter is great for that. After the majority of the oil soaks up into the litter you scoop that up, then put a little more on the stain that will still be there. Grind the new dry kitty litter into the oil stain with your shoe until it looks like dust, then sweep that up. You may have to do that several times to get it all the way up. After all that, (I assume the driveway is cement) you can get it a little damp and put some laundry soap on it and scrub the spot. Eventually it will get most if not all of the oil up. Have fun!