If you want to borrow money to buy or improve your home, you must be credit-worthy. But for the hundreds of millions who live in shantytowns, borrowing is out of the question - or is it?

In this week's Earth Report we find out about the innovative savings and credit schemes that are helping the poor improve their homes and their environment.

Phnom Penh, Cambodia

Years of civil war has left Cambodia with little infrastructure and a shattered economy. Over a third of the country survives on less than a dollar a day. For the poor in the countryside, getting a job in the capital is seen as an escape route from their hardship. But here they face new hardships: Phnom Penh is so overcrowded families are forced to find shelter in the rooftops.

But there is hope and it's coming not so much from the ground up as from the roof down.

Cooperative saving schemes, provided by NGOs like Solidarity for the Urban Poor Federation, are making the poor credit-worthy. Each family is encouraged to save a dollar a week, which is invested in a group saving scheme. This way roof dwellers can get loans for emergencies and improve their homes. What's more, cooperative saving has helped strengthen this community and create new alliances with other groups. This has resulted in the creation of the Urban Poor Development Fund whose members are petitioning the government - with its access to foreign aid - to channel funds through their savings and loan structure.

Durban, South Africa

When the ANC came to power in 1994 'Homes for All' was a key election promise. Today, the housing crisis remains as one of the government's biggest problems and millions of people still live in vast informal settlements known as townships.

Recognising the enormity of the task the South African Homeless People's Federation (SAHF) - a community based organisation - is working with a local NGO, People's Dialogue, to help create people-driven solutions.

In Durban, where more than half its 2.5 million population live in informal settlements, savings and loan schemes are giving poor families the chance to realise their dream of building their own homes on secure land.

The SAHF is so successful it has more than 100,000 families contributing into a network of 1100 savings and credit collectives throughout Africa.

Manila, The Philippines

Chronic overcrowding means that more than half of Manila's poor live in shanty towns. Payatas is a 21-hectare rubbish dump within Metro Manila where people scavenge a living from the city's waste. Here, thousands of scavengers and their families live on or nearby the rubbish tip. It's an unhealthy, dangerous place that claimed the lives of hundreds of people when a catastrophic landslide of rubbish buried their homes in July 2000.

In order to move people away from the danger zone, the residents set up a rubbish-pickers savings scheme. With the help of the Philippines Homeless Federation and regular cooperative saving, the residents of Payatas bought an area of land for 4.5 million - 3.9 million of which came from the saving's scheme. Here, 309 families live on safe, secure land.

Today, the Federation is so successful there are 200 similar groups across The Philippines.

Jinja, Uganda

The gradual upturn in Uganda's economic fortunes has yet to benefit the people who live in Mpumudde, the most deprived part of Jinja, the country's second city. Very few of the 20,000 inhabitants of Mpumudde have a job. For women whose husbands cannot find work, the only source of income is from distilling a local gin called 'waragi'. In the ramshackle brewery distilling waragi can be dangerous work and - in its raw form - is a killer.

But instead of trying to stamp it out, the authorities have listened to the community. The message was keep this dangerous living but make it safer to make and to drink. A breakthrough came with money from DfID's Community Challenge Fund, which helps finance schemes devised by poor neighbourhoods. The funds will be used not only to buy safer distilling equipment and help them establish their own businesses but also to build homes.