Viktor Troicki of Serbia competes during the World Tennis Challenge at Memorial Drive on January 9, 2013 in Adelaide, Australia. These epic images are inspiring! Who says tennis is a fairy sport?

Masses of people die from poor sanitation around the world, due to the fact that they don't have clean toilet access. Bill and Melinda Gates Foundation has been heavily involved in funding sanitation projects, to reduce this problem. They've put in almost $150 million into them. Their latest investment is in the Caltech Toilet Reinvention Project. This future toilet in the making is going to be cheap, hygienic, solar-powered, self-cleaning and will convert urine and waste into hydrogen and fertilizer. Caltech received $1.6 million in funding and will have the prototype ready to ship to Africa, with a price tag of approximately $2,200 by December 2013.

The world is changing and so are the big cities, which are in a race to make life better for us. Here are the top ranked North American cities compared by a device called the "Smart Cities Wheel". The rankings are based on 3 main categories: technology, sustainability, and good living conditions.