BBC News: Tagging 'takes off for web users'
From the BBC:
"As more and more people put their own content online, they are also being invited to tag it with descriptive keywords to help organise their data. According to the Pew Internet and American Life Project, the trend in tagging is growing among US web users. It found that over a quarter of online Americans - 28% - had tagged content such as a photo, news story or blog."