What is it: Google Sidewiki allows you and others to highlight any section of a web page to either comment on highlight or make a reference point to. It is free and installs in a flash.
How can I use it in my classroom? If you want your students to read a passage from a website you can now highlight the section, pose a question in the sidebar and start a discussion from within the page through Google Sidewiki. All users must be registered so anonymous comments cannot be made.
Check out the video below for a visual demo and sidewiki is available here.