If you care about global health, sanitation or just clean water, then you'll care about the eighth annual World Toilet Summit and Expo in Macau, China. This conference of the World Toilet Organization (not to be confused with that other WTO) aims to figure out how to get some form of sanitation to the planet's 2.5 billion people—more than one in three— who do not have proper toilets.

The lack of such basic  facilities leads to contamination of food and water, disease, and a host of other environmental and health problems.  The solution may seem simple, but it’s not: the developed world's flush toilets will not work in areas where water is scarce.

Some  possible remedies include dry latrines, cooking fuel made from fermented human waste (biogas) and even solar-powered toilets. They may not be as fancy as the robo-toilets of Japan, but they get the job done.

Credit: istockphoto.com