Here are some screenshots of Twilight on the iPhone. Notice that here, you're not only buying the e-book, but also the reader packaged with it. Looks like a slick interface with strong usability.
From the description of icebergreader:
Iceberg is our revolutionary new electronic reader. Iceberg brings the timeless experience of reading books to the mobile space, wedding the functionality of the iPhone to the feel and familiarity of books.
Iceberg is different from all other existing electronic book readers – it’s the only one that replicates the actual experience of reading a book. It’s all done in an organic way that feels right to people who love to read.
With Iceberg:Each and every book exists as its own application right in iTunes. It’s the fastest, most convenient way to purchase books electronically.
Iceberg maintains pagination. This means that every one page in an Iceberg book is equivalent to a page in a print copy of a book.
Text can get bigger and smaller as readers pinch in and out. But Iceberg text reflows automatically so there’s no annoying scrolling across the page.
Readers can search text, take notes and skim through pages, all in an organic and intuitive interface that readers will love.
Iceberg also makes it easier and more fun than ever to discover and buy new books. Each book acts as a gateway to other titles in the bookstore, which is located right inside of iTunes. Readers can buy books instantly, as soon as their interest is piqued. They can get books when they want them, wherever they are – anytime, anywhere.
There are more "books" available for the iPhone - many of them free, but even at that rate we're only talking 680 titles - just a tiny fraction of what's available for the Kindle.
A little teaser for tomorrow - what if you could carry around the works of Shakespeare - all of them - on the iPhone - for free!