Jack Dorsey, the founder of Twitter, failed many times before succeeding in his venture.

One is Jack Dorsey, a co-founder of the popular Web service Twitter.

I said yeah, it's really - it's Jack Dorsey, the guy who started Twitter.

Jack Dorsey, American software architect and businessperson best known as the creator of Twitter.

Jack Dorsey is an American software developer and business person.

Jack Dorsey, a co-founder of Twitter, said high-speed social networking can become a moneymaker.

Jack Dorsey, most famous for co-founding Twitter, is not content with having set the world of communication alight.

Twitter has become very popular worldwide since Jack Dorsey created it in 2006.

Twitter co-founder Jack Dorsey's recitation of a long list of political leaders now using this new medium shows that its impact is global.

That could explain the Tweet from chief executive Jack Dorsey yesterday who said he was looking forward to a big week.