Jan. 4, 2010 -- The Burj Khalifa (formerly known as the Burj Dubai) opened today, officially becoming the world's tallest building. Standing at a height of 828 meters (2,716 ft) tall, the United Arab Emirates (UAE) landmark has more than 160 stories, the most of any building in the world. The tower has a 360 degree observation deck on the 124th floor and plays host to the world's first Armani Hotel. The Burj Khalifa will ultimately become a community of 12,000 residents all using the building's self-contained facilities for work, home and recreation.

SLIDE SHOW: The Burj Khalifa may be the tallest building in the world, but how tough is the competition? Browse the World's Top 10 Tallest Buildings to find out.

Although new skyscrapers are completed every year internationally and the much coveted "World's Tallest" record is always being broken, the Burj Khalifa -- named after UAE President Khalifa Bin Zayed -- towers over its nearest competitor (the 508 meter tall Taipei 101 in Taiwan) by an impressive 320 meters (1050 ft).

--Ian O'Neill, Discovery News