Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

Some people use paper as their canvas for creating works of art, Patrik Bundeli, on the other hand, uses Ping-Pong balls. His steady hand turns simple white balls into elaborate cartoonish faces. Some of his works feature black and white gothic visages, while others have adorable little snouts. The latter ones would make a wonderful addition to any working place, putting smiles on everyone’s faces. (Photo by Patrik Bundeli)

Fukusawa Takayuki is a Japanese designer, whose life’s goal is to brighten up the people's mood through his creations. His latest project sure does the job. In this project he created a number of figurine-pendants called the “Tanima Diver”. When worn by a woman with full breasts, it looks like the figurine is making a dive into her cleavage. Though only the most outgoing of girls will allow herself to wear such a necklace, it will surely bring a wide smile to the face of any man. (Photo by Takayuki Fukusawa)

The selfie is the most popular photography trend of the internet today. It's gotten so popular, in fact, that even our beloved feline friends have started to catch on. I dare you to keep the smile off your face for this one!

With more than 40,000 followers on Twitter and 26,400 fans on Vine, it looks like Marutaro the hedgehog from Japan is one of the most popular hedgehogs on the Internet. And as his owner keeps on posting Marutaro’s pictures online daily, Marutaro’s popularity continues to grow. There are hundreds of cute photographs and videos of this little fellow, but the ones with little paper cut-out faces are probably the cutest. As Marutaro lies on his back, his owner gives him a variety of silly expressions and smiles. The 20 best of them will definitely boost your mood!

Photographer Brian Finke spent nearly two years traversing the friendly skies, following the life of flight attendants in the air and on the ground, from Delta and Hawaiian Air, to Hooters Air, Southwest, Air France, British Airways, Air Asia, and dozens more. His images of flight attendants waving, applying makeup and deboarding plans while smiling appear as if they were ripped from an advertisement in a glossy magazine. Here: Tiger Airways, Singapore, 2006. (Photo by Brian Finke/The Washington Post)

Latvian cyclists have decided to show the automobilists just how absurd it is to have only a single occupant in a car. The car takes up an enormous amount of space on the road; however, everyone is so used to it that no one ever notices it. It’s not hard to guess the thoughts of automobilists, and how they cursed those cyclists for taking up so much space. However, they have only themselves to blame. If everyone rode only bicycles to work, then there would never be such a thing as a traffic jam, the air in the city would become cleaner, while people would live longer, healthier lives, since cycling is a wonderful way to use the extra fat on your belly as the “fuel” for your bike.

The artworks that Alexa Meade makes are very unique and original. A usual painter creates a 2D or a 3D drawing on flat 2D surface. Alexa, on the other hand, draws over the body of a regular person, making them look like a 2D painting. The pictures of these people are almost uncanny, as you realize that the eyes “paintings” are real, and suddenly it dawns upon you that you are seeing a living and breathing human being. It is weird how we perceive this world, and how easy it is to trick our brain into thinking that it’s seeing a two-dimensional object. (Photo by Alexa Meade)