World's tallest building to go up faster than gestating baby

A Chinese construction company that's climbed to the height of viral video fame by documenting its head-spinningly fast building techniques has set a lofty new goal: constructing the world's tallest building in only nine months. For perspective, Dubai's 2,717-foot-tall Burj Khalifa (shown here) -- which the new building, Sky City, in Changsha, China, is expected to best by about 33 feet -- took six years to construct. The Broad Group began work on the 220-story structure in April and plans to complete it in January. Its speed secret: prefabricated building components. Raise your hand sky-high if you're looking forward to watching the YouTube time-lapse video of this one.