A friend of mine without internet access asked me to ask this question.

How do you get oil stains out of a driveway from a car that leaked oil?

She tried kitty litter and some other stuff but she said that she can't get rid of the stains.

There is a product called Pour-N-Restore which you pour on the stain and it dries to a powder and rinses off.It is biodegradeable and has an orange odor. It comes in gallon containers and is available at Ace Hardware stores, etc.