This document discusses various Web 2.0 applications that can be used in blended learning, including networking, bookmarking, publishing, collaborating, aggregating, and crowd sourcing. Networking involves building online communities through social networks and interactions. Bookmarking allows users to organize and manage web page bookmarks with tags. Publishing gives users tools to create and share their own online content. Collaborating facilitates working together over the internet. Aggregating combines different online sources into a single meaningful view. Crowd sourcing uses public networks as an information source.