Teenagers today, goes the complaint of many parents, spend more time in a virtual, online world than they do in the real one. Instead of exper-iencing life and meeting people, they waste their time staring at a screen that exposes them to almost unlimited perils ranging from pro-anorexia websites and pornography to violence and even suicide death cults.

But, as two very different projects on opposite sides of the globe demonstrate, young people are also harnessing 21st-century technology to turn their lives around. In places where real-life communities are divided and dangerous, the internet can be the safest place for young people to connect with each other and make their voices heard.

Ivânia Tupinambá lives at the edge of a city at the end of a peninsula. The Plataforma district of Salvador, Brazil, is, in the words of a local teacher, “on the way to nowhere”. People born there usually stay put, trapped by low or non-existent incomes and poor education. It is the sort of place where even many long-term residents of Salvador never stray. And so, despite living in an area where community workers estimate that 90per cent of people do not have access to a private computer, 19-year-old Ivânia finds out about the world - and tells the world about her - via the internet.

Courtesy of a charitable project called Kabum - a brightly-painted art and technology school that has taught her photography, helped her to set up a blog and given her access to a dazzling array of flat-screen computers and image editing technology - Ivânia is as multimedia savvy as the best-equipped British teenager.

She has a newly broadened window on the world, and with it a dream to go to Africa. But, thanks to themed modules at Kabum on identity and community, and projects such as her photographic blog and a student-produced newsletter, she also has a fresh perspective on her own often-forgotten neighbourhood. Ivânia is quietly proud of where she is from: “By taking photographs of poverty, I want to show my community.”

Physical interaction is not always straightforward, or even safe, for Brazil's young urban poor. Salvador is a place where the streets can be the preserve of hawkers and vendors at best, or at worst of drug dealers, child prostitution and police brutality. Ivânia and the pupils and teachers at Kabum, located in another deprived suburb called Nordeste de Amaralina, have to be out of the building by 7pm prompt or spend the night in a classroom, because criminals don't want people on the streets after dark.

Teenagers such as Ivânia are using the internet as a means to bypass the dangers of their physical environment. Whether by posting films about teenage pregnancy or teaching their unemployed parents how to apply for jobs through websites, they have found a platform from which to speak.

The virtual world is also being used as a means to make sense of the real one. At Casa Brazil, a community centre only minutes away from Ivânia's home, staff use the violent online games that children play in the computing room as a way to talk to them about the all too real violence in their own lives.

“We are taking what children like to do, working using the computers and trying to put something instructional inside it,” says Haroldo Silva Barbosa, the centre's 30-year-old co-ordinator.

Once at Casa Brazil, they can take courses such as web design, do their school homework with the help of computers that are absent from their classrooms, or simply surf the net under the watchful eye of Haroldo and his colleagues.

“For sure, some of the things that the young people are accessing worry me,” he says, describing how he recently watched one student looking at a picture of a half-naked 12-year-old girl. “But if they're here, we can raise their consciousness of what's OK and what's not.”

Carla Aragão, of CIPO, the Brazilian NGO that supports both Casa Brazil and Kabum, says such projects know how to reach their “target market”. By exploiting young people's fascination with all things high-tech, they engage them long enough to teach skills that will be vital in the job market: “We are competing with other things and, without the technology, I don't know whether we would be able to keep them here.”

But “educommunication” and “digital inclusion” projects such as Kabum are also about teaching people from deprived areas to work together, both within individual communities such as Plataforma and across Brazil.

NGOs including CIPO have already established the “Good Attitude Network”, a website on which young participants in such projects can pool ideas and campaign for children's rights. This is Facebook-style “social networking” but with a purpose, and the hope is that its political clout will grow as the numbers expand, with the help of a £500,000 Unicef-BT partnership that will shortly extend “educommunication” to 10,000 more young people from five Brazilian cities.

Carla says she is creating “skilled labour but also active citizens”, and Ivânia agrees. Having just graduated from Kabum, she is saving up to buy her own camera and plans to teach photography to children and young homeless women as a means of explaining “their rights and duties as citizens”.

“We are using the technology well, using it to communicate something important”, she says. “It is not just entertainment for us.”

Having left prison at 21, with little to put on his CV except a criminal record, Daniel Fraser needed support if his dream of setting up his own business was ever going to succeed. A dad himself, he wanted to establish a nursery service that would also encourage the young, often black, fathers in his inner-city Birmingham neighbourhood to participate in the upbringing of their children.

His plan for Daddy's Daycare was receiving positive feedback from everyone he told about it, but Daniel lacked the business skills to launch his project and the confidence to talk to the “upper-crust people” whose backing he would need

Inner City Creative Media Group (ICCMG), a social enterprise that provides multimedia and business training to “gang affiliated or affected” young people in Birmingham, offered exactly the help that Daniel sought. Getting to the ICCMG offices, however, was no simple task.

Daniel, now 23, is from Handsworth, part of Birmingham's northwest corridor that includes Aston, Lozells and other neighbourhoods that have become synonymous for many outside the city with gangs, crime and riots. His journey to ICCMG's offices meant crossing postcodes where he was not welcome. “There is no way I could have walked there fast enough. A car would have pulled up. They would have asked me where I was from and beaten me up, stabbed me, or put me in the boot.”

Although never a gang member, Daniel had ended up in prison having “followed the wrong crowd”. In the end, it was driving around the streets of Handsworth while already banned that landed him inside.

Justice Williams, the dynamic, 27-year-old founder of ICCMG who herself secured a criminal record by spending time with “the wrong sort of people” a few years ago, was all too aware of the problems that young men such as Daniel might face. So she invites people to contact her online, and lends computers to those who need them. Daniel took literacy and numeracy courses from his home, and completed most of Justice's “creating successful entrepreneurs” programme in the same way.

A young man who, in his own words, had previously used the internet to “look for girls on chat rooms” learnt how to put together a business plan, research his competition, create a website and advertise, using social networking sites such as Facebook and MySpace.

Justice established a Yahoo group and a Facebook network for her young entrepreneurs, and says that they have taken to the idea with gusto: “It's not about where you're from. It took territory and geography out of it. We had a guy from Aston and one from Handsworth whose brothers are quite notorious and they got on fine.”

These people began to meet up in person, and “realised they were in the same boat”. The young man whose brothers ran a gang now runs a communications centre and after-school club that offers internet access and online gaming and links children with their peers around the world.

His business plan now finalised, Daniel is searching for premises and hopes to launch Daddy's Daycare in the near future. Justice, meanwhile, is about to launch another element of her internet community with an online television station, Just TV, which will provide a platform for young film-makers - including some trained by ICCMG - to show documentaries about their lives and neighbourhoods.

“They already use MySpace, Facebook and all that,” she says. “I want to use that, but in a positive way, to get them to engage with each other.” So far, she thinks, it seems to be working.

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