The discussion on this topic about the pros and cons of electronic vs paper books makes me wonder if you could mitigate against one of the negatives (remembering the position of text on page) with a book-reading view of some sort. The most obvious candidate would be fixing reading mode which at the moment is almost unusable to me (reading line by line all the way across a widescreen monitor just causes eye strain).
Instead of:

I don't see why you couldn't do something like this for any book that has page numbers:

This would be particularly brilliant in the iPad app, where it would feel like sitting down to read a book...