To put their significance into context, Expos, or World fairs as they're originally known, are held every five years or so, and are described in Wikepedia as the world's third largest event in terms of economic and cultural impact after the Olympics and the football World Cup.
The World expos date back over a hundred and fifty years and at first focused squarely on trade and industry and innovation - the very first expo in London in 1851 was called The "Great Exhibition of the Works of Industry of All Nations."
Sweden played its part in broadening the focus of the Expos when it held its own in Stockholm in 1949 when the emphasis was shifted onto cultural significance and utopian ideals.
This year's World Expo in Shanghai follows this line with the theme "Better city, better life" looking at innovative ways for improved living conditions in future city environments.
Focusing on this task, each country builds its own pavillion, a form of nation branding. Sweden's pavillion in shanghai , which is still under construction, has the theme Swedish "Spirit of innovation," which was underlined when the pavillion theme was unzipped, rather than unveiled. (Sweden having invented the zipper!)
Seventy million visitors are expected over the six months of Expo 2010.