iBooks Author is a free program for creating multi-touch, interactive books for Apple's iPad. While iBooks Author is free it will only run on an Apple Macintosh running Lion or Mountain Lion (note some people figured out how to make it work in Snow Leopard). It is as easy to use as Pages or Keynote. If you already have your content you can have a professional looking ebook together in very little time.
I'm excited about iBooks Author because it gives me a chance to create textbooks that match my pedagogy. It is the tool I create, so it can go along with the primary way we learn in class.