To help us visualize the world's need for water, Matthew Laws and Hal Watts (with photography by Luke Bennett) illustrated the projected use of urban water in various countries by 2030 with kitchen sponges:
Combining their engineer's precision with creativity honed at the London Royal College of Art, Matt and Hal first designed a world map entirely out of cheap kitchen sponges. They then poured water onto each country in amounts proportional to that its expected urban water consumption in 2030. Elegantly literal, the sponges grow in height according to how thirsty the country will be, generating a stark topography of future needs for urban domestic water.
Core77 has the making-of video clip: Link