If we divided the surface of the Earth equally between its 6.5 billion human inhabitants we would each have an area of land 22,898 m2 (2.3 hectares, 5.7 acres). In the pictures below, that area has been formed into an island 107 metres x 214 metres, surrounded by our share of the ocean. The types of land available: grassland, woodland, urban, desert, etc. has also been shared out fairly on this 'allotment'.
Oblique view of our 'allotment' with a person for scale.
Allotment Island - our share
Just 0.2% of the land is urban, which means our share is a patch of urban land just 7 m x 7 m. Over 50% of us live in urban areas. Land use will change as the population grows, and our 'allotment' will shrink. When the World's population reaches 9 billion, we will each have an area just 182 m x 91 m (1.7 hectares, 4.1 acres).
Few of us actually do own as much as 2.3 hectares of land. Most of us own nothing (apart from the land we own in common with others, for instance because it is controlled by our government). Nevertheless, we all depend on our 'allotment', which means we have to rely on other people (on the whole, rich people) to look after it for us. Now, I've got nothing against rich people, but I'm not sure how reliable they are when it comes to looking after my allotment.
See also: Land cover islands: a vision of a tidier world
Data: IIASA (http://www.iiasa.ac.at/Research/LUC/GAEZ/tab/t44.htm)