Removing an oil stain from concrete

[H-townbenzoboy]

I searched, and I could not find a definate answer to my question. I have no problems with our driveway having oil leaks, two diesels occupy it, they're simply marking their territory. But my brother however does not like it. His niece has moved in with his family, and her gasser Mitsubishi needs an engine rebuild and has an oil leak. It's gotten oil in his garage, driveway, and on the street in front of his house, all concrete structures, which are fairly new. What's good for cleaning up oil? Somebody told me kitty litter, but I'm not sure.
-Joe