The long-dreaded moment has come true:

A 1,680ft skyscraper has become the tallest building in the world, according to developers.

The Burj Dubai is expected to be finished by the end of 2008 and its planned final height has been kept secret.

But it has already started to edge ahead of the 1,667ft Taipei 101 in Taiwan, the tallest building since 2004.

The state-owned development company Emaar Properties said the tower would stop somewhere above 2,275ft.