Given how crappy Windows Vista & Windows 7 were, it's fitting that Bill Gates' "next big thing" is a toilet

Perhaps the single greatest innovation to improve public health was the creation of safe sanitation — the toilet. But for 2.6 billion living in the developing world, their inability to take care of business cleanly results in massive contamination, causing nearly 1.5 million child deaths every year.

In response to this tragic figure, the Bill and Melinda Gates Foundation asked innovators to “reinvent the toilet,” a feat not accomplished since 1775. The winners were announced this week.

Among the “next generation” of toilets is one that use microwave energy to transform human waste into electricity and another that captures urine to use it for flushing. One toilet even turns waste into charcoal.

“Many of these innovations will not only revolutionize sanitation in the developing world, but also help transform our dependence on traditional flush toilets in wealthy nations,” foundation co-chair Bill Gates said.

The foundation’s parameters for this toilet of the future required that it operate without running water, electricity or a septic system, infrastructure lacking in the developed world. It also could not discharge pollutants, and must operate on five cents a day.

“Innovative solutions change people’s lives for the better,” said Gates. “If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world’s toughest problems.”

The Bill and Melinda Gates Foundation also announced a second round of grants that totaled $3.4 million to continue researching this problem.