The document discusses various Web 2.0 tools that can enhance classroom instruction, including blogs, wikis, social bookmarking, photo sharing, podcasts, and voicethreads. It provides examples of how each tool can be used, and notes that many are free online applications. Key tools covered are blogs for instantly publishing information, wikis for collaborative editing, Flickr and other sites for photo sharing, and podcasts for digital audio files that can be shared.