After having been exposed to two essential influences-
George Monbiot's inspiring book The Age of Consent -A Manifesto for a NewWorld Order
Ben McLeish's Zeitgeist interview with Richard Morley of the Molecularism movement
I've come to fully appreciate the need for a world parliament, especially since the three great crises facing humankind are global in nature- Environment, Economy, and Energy -we'll need a global body to address them.
And that's not the United Nations, sadly. (George Monbiot completely demolishes the UN in his book mentioned above, while Richard Morley articulates an excellent understanding of the alternative to this as a three branch world government made up of Representatives, Experts and the People themselves).
I was most interested by how you would go about representing the entire population of the planet so I made a rough image based on population size. See pic below.
If I have time I would like to rearrange this image so that all the countries are arranged according to their geographical location (for instance all the African countries next to each other, etc).
I have a lot more to say on this, but I'll leave that for another time...