Consumers International has been around since 1960 and describes itself as serving "as the only independent and authoritative global voice for consumers." It's useful for a more worldly perspective on consumer issues and has lots of media-related reports and projects on such topics as irresponsible drug promotion, junk food marketing, the mobile phone industry and communication about climate change as it relates to consumerism.
Check out these reports and briefings:
Left Wanting More: Food company Policies on Marketing to Children (March 2009)
New Media, same Old Tricks: A Survey of the Marketing of Food to Children on Food Company Websites (March 2009)
Drugs, doctors and Dinners: How Drug Companies Influence Health in the Developing World (October 2007)
Research Briefing: Promotion of Prescription Drugs in the Developing World (2009)