DIY Fire Pit Table Top - The Lilypad Cottage...you can also just take the base off of a round dining room table or take one side off of the large cable spools if you want to make one of these very easily. Cheap second-hand round tables & cable spools can be found cheaply on craigslist/thrift stores.
Tell Marcus about zinc (seen here on this table top) for countertops instead of concrete. I love them. And, I think as they get stained, they develop a cool patina. The material doesn't look too expensive either.