Dubai Rotating Tower

Dubai rotating tower with 420-meters (1,378 ft) height and 80 moving floors in Dubai, United Arab Emirates is designed by architect David Fisher.
Each floor will be able to rotate independently. This will result in a constantly changing shape of the tower. Each floor will rotate a maximum of 6 meters (20 ft) per minute, or one full rotation in 90 minutes.
 

The Dynamic Tower in Dubai will be the first skyscraper to be entirely constructed in a factory from prefabricated parts. So instead of 2000 workers, only 680 will be sufficient. Construction is completed in 2010 and estimated cost is 1.2 billion AED (US $330 million - Euro 255 million)

REFERENCES:

http://news.bbc.co.uk/2/hi/middle_east/7472722.stm

http://en.wikipedia.org/wiki/Dynamic_Tower

http://www.strangebuildings.com/rotating-tower-dubai-uae/