The UN secretary general has called on the world to do more to narrow the technology gap between rich and poor.
Africa countries like Senegal are appealing for more funds
Opening the World Summit on the Information Society, Kofi Annan said nations had to show the political will to bridge the digital divide.
The Tunis summit had been threatened by a row over US control of the net.
A last minute deal left the US in overall technical control, with an international forum being set up to discuss internet issues.
The UN has also had to contend with criticism from human rights groups at the choice of Tunisia as host country.
'Out of reach'
Some 170 countries and more than 20,000 delegates are taking part in the UN's largest ever summit in Tunis.
The aim of the three-day meeting is to look at ways of using information communication technologies to help improve living standards in some of the world's poorest nations.
A key aim under the UN's Millennium Development Goals is to connect all the villages of the world to the internet by 2015.
But worldwide only 14% of the population is online, compared with 62% in the US.
In his address to the meeting, Mr Annan said that "for far too many people, the gains remain out of reach".
"There is a tremendous yearning, not for technology per se, but for what technology can make possible," he said, urging delegates to take action.
"The hurdles are more of a political than financial nature," he added. "It is possible to lower the costs of connectivity, computers and mobile phones."
But money remains a key issue. A voluntary Digital Solidarity Fund intended to help finance technology projects in developing countries has so far only raised $6.4m (£3.68m) in cash and pledges.
However, many richer nations are cautious about providing more aid, arguing instead that developing nations should be looking at drawing in more private investment.
"The challenge to the developing world is now to make sure they have the infrastructure, rules, legal processes and the market systems to attract the investment of the technologies that we see on display at the summit," said US Assistant Secretary for Commerce Michael Gallagher
Mr Gallagher described the deal reached on internet governance as a "win-win" outcome.
"It's a very bright future ahead," he said. "Freedom rings for the internet."
Nations such as China and Iran had been pushing for an international body under UN auspices to oversee the net.
But the eleventh-hour agreement leaves the day-to-day management of the net in the hands of the California-based Internet Corporation for Assigned Names and Numbers (Icann), which answers to the US government.
Instead an international forum will be set up to discuss net issues such as spam and viruses, although it will not have any binding authority.
Tunisia under pressure
The choice of Tunisia as a venue for the summit has been criticised by human rights groups, which accuse the government of President Zine El Abidine Ben Ali of press repression.
In a statement, three UN human rights envoys said they had received "numerous reports" of abuses and that respect for human rights was deteriorating in Tunisia.
Tunisia opposition figures are staging a hunger strike in Geneva
The envoys said they were concerned about the deterioration in the freedom of expression, of association and of the independence of judges and lawyers in Tunisia".
On Tuesday, France called on Tunisia to uphold press freedoms following an attack on a French journalist.
"I realise there have been problems," said Mr Annan. "I have not only read about it, I have myself raised this issue at the highest level, including with the president of Tunisia."
"Sometimes by organising these conferences whether in a country like Tunisia and others, and putting the spotlight on them, where these issues of human rights and others are discussed, it's extremely helpful and it helps push the cause forward."
The Tunisian government rejects any suggestion that it violates human rights or limits legitimate access to traditional or electronic media.
WSIS takes place in Tunis from 16 to 18 November.