Online textbook rental service Chegg announced today that it has acquired Student of Fortune, a site where students tutor each other. Chegg also recently acquired Cramster, Notehall and CourseRank. With each acquisition the company becomes more than a textbook service, as their newly-revamped website now features a “homework help” section and courses section that offers schedules, reviews and grades distributions. Chegg also now offers an HTML5-based e-reader for textbooks. [Mashable]