By Jonathan Fildes
Technology reporter, BBC News, Oxford
Tech's inroads to a "global society" will influence its governance, Mr Brown said
Technology means that foreign policy will never be the same again, the prime minister said at a meeting of leading thinkers in Oxford.
The power of technology - such as blogs - meant that the world could no longer be run by "elites", Mr Brown said.
Policies must instead be formed by listening to the opinions of people "who are blogging and communicating with people around the world", he said.
Mr Brown's comments came during a surprise appearance at TED Global.
"That in my view gives us the first opportunity as a community to fundamentally change the world," he told the TED Global (Technology, Entertainment and Design) conference.
"Foreign policy can never be the same again."
The prime minister talked about the power of technology to unite the world and offer ways to solve some of its most pressing problems.
He said that issues such as climate change could not be solved alone, adding that digital technology offered a way to create a "global society".
"Massive changes in technology have allowed the possibility of people linking up around the world," he said.
In particular, he said, digital communications offered the possibility of finding common ground "with people we will never meet".
"We have the means to take collective action and take collective action together."
He talked about recent events in Iran and Burma and how the global community - using blogs and technologies such as Twitter - was able to bring events to widespread attention.
He also highlighted the role of technology in recent elections in Zimbabwe.
"Because people were able to take mobile phone photographs of what was happening at polling stations, it was impossible for [Robert Mugabe] to fix that election in the way that he wanted to do."
But Mr Brown also stressed the need to create new organisations to tackle environmental, financial, development and security problems.
"We are the first generation to be able to do this," he told the conference. "We shouldn't lose the chance."
He said that older institutions founded after the Second World War, such as the United Nations or the International Monetary Fund, were now "out of date".
"You can't deal with environmental problems through the existing institutions," he told the conference.
TED Global is an invitation-only conference dedicated to "ideas worth spreading".
In the past figures such as Al Gore have addressed TED
Each speaker - including the Prime Minister - is given 18 minutes to present to the audience.
Most talks are given by designers, technologists and scientists. However, events - usually held in the US - have seen talks by former US presidents and Nobel laureates.
Mr Brown was given an additional 15 minutes for questions and answers.
"Can I say how delighted I am to be away from the calm of Westminster and Whitehall," he joked at the beginning of his speech.
The Prime Ministers talk was met with applause. However, members of the audience, commenting on Twitter, were also sceptical of his speech.
"I hope Gordon Brown listens to his own words of wisdom at TED and actually makes change rather than talking about it - again," read one.
The Prime Minister was brought on stage at the end of the first session of the conference.
Previous speakers had included Swiss philosopher Alain de Botton and British comedian and tech enthusiast Stephen Fry.
This year's conference runs from 21 to 24 July in Oxford, UK.