An official `Tweet button` has been launched by Twitter to enable you automatically share external pages on the micro-blogging site.

The button sits on third-party websites - and can be added to pages by web editors - making sharing external links easier.

When the button is pressed a pop-up box appears with an automatically shortened version of the URL of the page you are on.

A Tweet can then be written around the link and it is posted using your username. You`ll need to be logged into Twitter for the function to work.

BDST: 1515 HRS, 14 August 2010