The 72-meter tall Phone Tower at the former headquarter of Ericsson at Telefonplan, in southern Stockholm, is a known landmark. It is the tallest building in the neighborhood for miles around.

Every night, the windows of the top ten floors of the now defunct Phone Tower lights up with different colored lights. And the colors keep changing according to the whims of the public. The lights are wired to a computer, that reacts to how people touch the number pad on their mobile phones.