At Apple's big news conference to introduce the iPad Mini, the company also showed off changes to its iBooks app.

The new version, available as a free download, will allow continuous scrolling of books, as an alternative to page-turning -- a computer-age shift in the reading experience. Standard page-turning was somehow comforting, as though deep inside the computer a book lived. So I'm not sure how much I'll like the scrolling feature. Will it seem too much like the reading I do at work?

Another interesting iBooks twist is the ability to share favorite passages or quotations by pasting them into social media sites such as Facebook and Twitter. It's a nice move toward fulfilling the ultimate promise of e-books, by expanding information through video/audio and sharing it easily with friends. 

Apple also announced that it now has more than 1.5 million books available, and that more than 400 million have been downloaded. Take that latter number, add in the downloads through Amazon and other sources, and you get a sense of the huge challenges facing brick-and-mortar bookstores. Quite a change in just a few years.