Photo: Thinkstock

We all have those days. You know, those days when someone in the elevator at work says, "Why so glum?" and you sputter to refute the glumness, only to wonder just what sort of face you were making. Those days when you just need someone to smile at you. Or maybe 7 billion someones to smile at you.

Good new: all of us smile-hungry humans have been invited to be part of a worldwide interactive art work: just upload this app and smile and, well, the whole world will smile with you. Pretty much, anyway. Yoko Ono (yes, that Yoko Ono) has been thinking about this project since 1967, when she said, "My ultimate goal in film-making is to make a film which includes a smiling face snap of every single human being in the world.” She just had to wait a few decades for the world of social media to catch up. Now she's launching this #smilesfilm app, with the ambitious, crazy, and awesome goal of collecting every smile in the world. Happily, the smilesfilm website shows everyone who's uploaded a smile (and you can see where they're from on the interactive world map). It's like a trip around the world and an instant pick-me-up all in one. Convenient. Smile.

Read More:
The Smile That Can't Be Stolen
6 Reasons to Smile Right Now