No. 4 Niklas Zennström, co-founder and CEO, Skype

Last year's position: 3

Niklas Zennström has dropped one spot on the Agenda Setters list from last year but you'd never have guessed - judging by the amount of noise surrounding his voice over IP company.

In the last 12 months, Skype has gone from internet upstart to wunderkind, signing up tens of millions of users to make free - or very cheap - voice calls using their computers. So popular is Skype that an ecosystem of third-party add-ons has arisen around it - and it's even managed to start bringing in some revenues.

Zennström reached such celebrity heights as to be photographed in the glossy pages of Vanity Fair along with Skype co-founder Janus Friis.

Much to the pleasure of company shareholders, Zennström brought about the archetypal happy ending for any internet star: a multibillion dollar buyout. In this case, by eBay.

But the Swede returns to the top five not for Skype hype but for his uncanny ability to pick the disruptive technologies. Before Skype, Zennström was the man behind P2P file-sharing bad boy Kazaa, so popular it caught the courts' attention.

Now VoIP upstarts such as Skype are stealing money from the big telcos - and have the incumbents racing to catch them up. Though the Agenda Setters panel agrees the telcos wouldn't be outrun forever, it's pioneers such as Zennström, who led the charge, that are bringing upheaval to the industry.

It's unclear how involved Zennström will be in the eBay-owned Skype over the long term but if he's not setting agendas there, you can bet he will be elsewhere.