You don't need to look for smiling faces to see how people are feeling in one city.

The Lithuanian city of Vilnius will install a giant monitor in town hall that will serve as a 'happiness barometer' to measure how people are feeling.

Here’s how it works: residents rank their mood on a scale of one to 10 and send their numbers to the town via phone and computer to come up with a tally that's fed to the screen for all to see.

Mayor Arturas Zuokas thinks it’s a fantastic idea that can serve a purpose:

This barometer is a great tool for politicians. If we take a decision and see a sharp fall in the mood of the city, then we know we have done something horribly wrong.”

The barometer may be just what the city needs. In 2011, Lithuania ranked as the fifth unhappiest country in the world.