Back in my young and impressionable years as an undergrad, we had to read 'The Selfish Gene' by Richard Dawkins. It was like my eyes opened for the first time, I couldn't get enough of the postulating. And it was in this book the concept of a meme was first introduced. He used the term 'meme' to describe how evolutionary principles could explain the spread of ideas and cultural phenomena.
A meme (pronounced /miːm/)consists of any idea or behavior that can pass from one person to another by learning or imitation. Examples include thoughts, ideas, theories, gestures, practices, fashions, habits, songs, and dances. Memes propagate themselves and can move through the cultural sociosphere in a manner similar to the contagious behavior of a virus.
Its delightful that the word he created to describe virus' like spread of ideas has spread like a virus over the internet....no accident, I'm sure.
I might have to read it again now.... see if it lights the same fires it once did!