Thought this was pretty cool, don't know if they'll actually pull it off:
They have done 30 stories in 15 days before apparently:According to its engineers, this will be the tallest skyscraper in the world by the end of March of 2013. Its name is Sky City, and its 2,749 feet (838 meters) distributed in 220 floors will grow in just 90 days in Changsha city, by the Xiangjiang river. Ninety days!
It's not a joke. According to the construction company, the skyscraper will be built in just 90 days at the unbelievable rate of five floors per day.