What do you like in a cloud? Is it colour, texture, shape? Would you like to compare your preferences with those of other people? Look no further than here. The site shows you tiny pieces of sky, which you rate. It figures out what you like, and shows you more pictures of that.
What does it mean? There's an article discussing all this on Artbash.
And if clouds are a bit abstract for your taste, there's always Kittenwar.