Social annotation products make the thinking of learners transparent, visible, and easily accessible for sharing with others, self-reflection, and feedback. This is accomplished by enabling almost any number of users to have threaded discussions linked to selected sections of a page. Three professors share their experiences with the use of a social annotation product, HyLighter, to enhance teaching, learning and assessment activities in three different areas of the college curriculum. One teaches screenplay writing. He describes how he used HyLighter to improve students' writing and critical review skills. A second teaches online graduate-level courses in pharmaceutical and forensic sciences. He describes the application of HyLighter to help students learn about chemical structures and related analytical principles. A third is a professor of educational psychology. She discusses her use of HyLighter to implement an alternative multiple-choice assessment approach in educational and developmental psychology courses. The chapter concludes with thoughts on the potential of social annotation technology to shift the focus of learning systems from content to be learned to what is going on inside the minds of learners. Collaborative or social annotation products enable users to have threaded discussions linked to selected sections of a page. This capability is in contrast to wikis which enable easy co-creation and editing of web pages but are limited for purposes of discussion. By making the thinking of learners transparent, visible, and easily accessible for sharing with others, selfreflection, and feedback, social annotation tools have the potential to shift the focus of learning systems from content to be learned to what is going on inside the minds of learners. After a brief description of HyLighter, a browser-based social annotation product developed by HyLighter LLC (see www.hylighter.com), three professors describe their experiences using this