Check out this slick online Sketchbook by Kevin Cornell (found via Witold Riedel).
The Prev/Next page button animation in the toolbar is expecially nicely done. I wonder if it could also encapsulate how far you are in the book--similar to a feature a slider would provide? If there was enough precision, maybe you could design in a way to jump to the end of the book, by clicking on that part of the button. Hmm.
A thumbnail or index view would also be nice, but nonetheless, I really like Cornell's clean online Sketchbook design.