Try and think of a Social Invention of your own design. Here is one that I thought of. Language is the barrier to most problems in the world today. I propose the creation of a common language, such as that of the old northwestern tribes of the United States using a trade language know then as Yakima Jargon. This language system could consist of either spoken word alone, or possibly a combination of words with hand signals. This language could be known as earthian.
Haha, that's funny. I thought of Esperanto the minute I saw the post! A pretty failed experiment, eh?