By Sanjoy Majumder
BBC News, Delhi
A World Toilet Summit has opened in the Indian capital, Delhi, with more than 40 countries taking part.
The four-day meeting will examine solutions and technologies that can be used to provide a basic need for nearly half the world's population.
According to estimates, 2.6bn people around the world lack access to a hygienic toilet.
The United Nations hopes to halve this figure by 2015 as part of its millennium development goals.
In India alone, more than 700 million people have no access to toilets which have proper waste disposal systems.
"It is as important an issue as anything," says Bindeshwar Pathak of Sulabh International, an NGO that promotes the use of low-cost toilets in India and is joint organiser of the summit.
"It is mostly the Asian, African and Latin American countries that lack basic sanitation. So that's what we will be discussing at the summit," he adds.
It is a sight familiar to anyone travelling around India by train.
Mr Pathak says toilets are an important issue
Early morning, many Indian villagers head to the nearest railway track and squat by its side relieving themselves.
Others use their fields, the forests or any piece of open land that they can find.
Women are particularly badly off - they either have to head out before dawn or in the night when it is relatively more private, but it means they are vulnerable to disease or even sexual assault.
The UN wants to remedy the situation by 2025.
But the problem is that it is quite expensive for most countries in the developing world to set up western-style toilets and sewage systems.
But there are alternatives.
Anita Jha, vice-president of Sulabh International explains, "We have several models of traditional Indian-style squat toilets. These range in cost from 700 to 3,000 rupees ($18 - $75) and also use very little water."
"That makes them very useful in countries with a water scarcity problem," she says.