Would you like to avoid making money on your ebook? If you do, then Garth Risk Hallberg, an author and extreme book designer, has a list of 7 ways to design a book so it will not work on the Kindle. (iPad is still a possibility, though.)
The list starts with a couple basics like using font colors and lots of high quality illustrations, but it then goes on to discuss all the various things you can’t show on an E-ink screen. Garth also provides a list of 10 books that are themselves Kindle proof, and he explains why.
If you’ve ever been curious about the cutting edge of book design then this list is definitely worth reading.