Try this:
Put some "powder" laundry detergent over the spill. It will actually soak up the oil.
Leave it for a couple hours. Sweep it up and do it one more time. Sweep it up again and just rinse the spot.
It works for me and most times you won't see the stain anymore.

Oh forgot to metion. It usally works best when you do it right after a spill.

Laters!