Check out 'The Digital Textbook'

I created The Digital Textbook as an alternative to paper texts which are static, generally only black-and-white, and often dated. In a world of so many types of text, some of which focus on words while others incorporate a range of media, it seems negligent to offer only the dry pages of an old textbook or novel. The Digital TextbookDigital Textbook is intended to be a dynamic, evolving site. If you find what I have included here does not meet your instructional needs, by all means steal the idea of such a site and create your own version that best meets your students' needs.  (from Jim Burke)

To view the resources at The Digital Textbook, click the above hyperlinked text.