Very important to note that in D6 you need to use &$form_state as the first argument in the actual form function, else it won't work. Documentation on this point is thin.
Universalis is an e-book. It gives psalms, prayers and readings for the seven daily Hours of the Catholic Church, plus Mass readings and a couple of other goodies. These all change every day, so the table of contents is a calendar. Tap on the date you want, select an Hour, and start reading. Obviously an e-book.
The new definition of an e-book is “something that comes in an ePub file” (or .mobi, or AZW, or PDF – it doesn’t change the argument). No-one notices the change, because all e-books come as files anyway, don’t they?
No. They don’t. They can’t. Universalis is the example I know best but I’m sure it isn’t the only one.
This article raises and interesting and important question. Appliances like the Kindle and the Sony e-Readers are really just substitutes for books, presenting a linear artifact in a digital form. Yet there is so much more possible that is just ignored by the Kindle and its ilk. Authors have at their finger tips great power in creating engaging interactive works that can draw a reader into the core of the story (or event, or idea). Simply dumping the latest best sellers into a locked-down markup and loading them on a screen in dazzling gray scale doesn’t really represent what e-Books should be.
For my part, I plan on providing law faculty and, later, students with a tool set in eLangdell that will allow for the creation of highly interactive course materials and case books which will not have direct print counterparts.