As of today, the Burj Dubai skyscraper in the Middle East stands at 650 meters, and here's a diagram found on the SkyscraperCity forums, comparing it to all the other towers. The construction has finally surpassed the current tallest man-made structure, the Warsawa radio mast in Poland, which stands at 646 meters. Only another 169 meters to go before the tip of the aircraft beacon is up, then. Clicky for bigger. [SkyscraperCity—thanks, Brian]