Children fill plastic containers with water from a well on a street, close to a neighbourhood called “The Tank” in the slum of Petare in Caracas, Venezuela, March 17, 2016. Although their nation has one of the world's biggest hydroelectric dams and vast rivers like the fabled Orinoco, Venezuelans are still suffering water and power cuts most days. The problems with stuttering services have escalated in the last few weeks: yet another headache for the OPEC nation's 30 million people already reeling from recession, the world's highest inflation rate, and scarcities of basic goods. President Nicolas Maduro blames a drought, while the opposition blames government incompetence. (Photo by Carlos Garcia Rawlins/Reuters)

A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

Yogis and street performers have been simulating levitation with nifty contraptions forever. They appear to be held aloft via nothing but their preternatural mental prowess. But are really enjoying the benefits of basic physics just like the rest of us when we use a chair. However, just because it’s perfectly explainable doesn’t mean it isn’t nifty. I’m especially impressed by this 2-person version and am still trying to work out how exactly the chair they’re using is shaped at the base.

Urszula Sidoruk, 19, from the paramilitary group SJS Strzelec (Shooters Association), trains her workout at a gym in Siedlce, eastern Poland March 18, 2014. Inspired by the war in Ukraine, growing numbers of Poles are joining volunteer paramilitary groups, where they receive basic army training and prepare to defend their homeland. (Photo by Kacper Pempel/Reuters)

Everyone wants to get something for nothing - whether it's a lucky upgrade that means you can turn left when you get on a plane instead or heading off into the economy seats, or even getting a few extra features thrown in for free when you buy a new car.

As some of the sharpest businesses around, no-one understands this quite as well as casinos and that's why they all have a system that they call comps. It's short for "complimentary offers" and these are special treats specially designed to reward you for your loyalty to the casino in question. They're basically bonuses.

A girl rides a donkey as another walks by at the Shawqaba camp for internally displaced people who were forced to leave their villages by the war in Yemen's northwestern province of Hajjah March 12, 2016. In northwest Yemen, one of the poorest countries in the Middle East, about 400 families uprooted by the war have been stuck in the Shawqaba camp in Hajjah province for the past year. Residents live in poorly built huts that protect them neither from summer heat nor winter cold in a camp that lacks the most basic services. (Photo by Abduljabbar Zeyad/Reuters)

(L-R) Maria Silva, Milena Cortes, Maria Arteaga, Jackeline Bastidas and Gissy Abello pose for a picture at the Famproa dogs shelter where they work, in Los Teques, Venezuela, August 25, 2016. Venezuelans struggling to feed their families let alone their pets are dumping animals on the streets, in parks and at makeshift homes overrun with scrawny animals amid an economic crisis. An hour from Caracas in Los Teques, hundreds of dogs bark and run around the streets scavenging for food outside a makeshift shelter. (Photo by Carlos Garcia Rawlins/Reuters)

A Turkana man and a boy carrying a gun look on as a G3 battle rifle hangs from a structure used to dry fish at a fishing camp on the shores of Lake Turkana, some kilometres from Todonyang near the Kenya-Ethiopia border in northwestern Kenya October 12, 2013The Turkana are traditionally nomadic pastoralists, but they have seen the pasture that they need to feed their herds suffer from recurring droughts and many have turned to fishing. However, Lake Turkana is overfished, and scarcity of food and pastureland is fuelling long-standing conflict with Ethiopian indigenous Dhaasanac, who have seen grazing grounds squeezed by large-scale government agricultural schemes in southern Ethiopia. The Dhaasanac now venture ever deeper into Kenyan territory in search of fish and grass, clashing with neighbours. Fighting between the communities has a long history, but the conflict has become ever more fatal as automatic weapons from other regional conflicts seep into the area. While the Turkana region is short of basics like grass and ground-water, it contains other resources including oil reserves and massive, newly discovered underground aquifers. (Photo by Siegfried Modola/Reuters)