Blogs were originally used a web based diary, but may now also be used more generally as a discussion site where people comment on a diary entry or article.
Podcasts are like a radio file that can be downloaded and listened to whenever the user wants to.
The New Rules of Marketing and PR : Content Marketing, Podcasting, Social Media, AI, Live Video, and Newsjacking by Browse the following links for a selection of websites with good information on Web 2.0 and other emerging technologies for libraries.
Social bookmarking allows users to keep track of their favourite sites, and then access them from any computer with an internet connection.