Among the 100 world's largest economic entities, 51 are corporations. The world's biggest corporation is General Motors, in front of countries like Denmark, Norway, Indonesia, South Africa, Saudi Arabia and Finland... and with Wal-Mart, Exxon Mobil, Ford, Daimler-Chrysler, Mitsui, Mitsubishi, Toyota, General Electric and Itochu edging out countries such as Portugal... Creepy.
http://www.corporations.org/system/top100.html