Lisa Rienermann's Type the Sky project uses the spaces between buildings to form the letters of the alphabet, from A to Z.
According to the blog Slanted, Rienermann's alphabet adventure started with one of the most distinctive letters: "It began with the 'Q.' I was in a kind of courtyard in Barcelona. I looked upward and saw houses, the blue sky and clouds. The more I looked, I saw that the houses formed a letter Q."
What I love about Rienermann's type is that while it's beautiful in its own right, it almost begs you to pay better attention in your own town to see what else might be hiding up there in the spaces between. "Look up!" it seems to say. "The sky is talking to you!"