My iPhone is always with me when I'm in the bookstore. Many times I've found a book that interests me, I pick it up and browse through it, then pull out my iPhone, open the Kindle app and grab the ebook sample (assuming one exists). I've even bought Kindle ebooks on the spot in a bookstore with my iPhone. I feel bad, sort of, but it makes me realize the enormous opportunity brick-and-mortar bookstores are missing out on.
eBook Apps Can Help Brick-And-Mortar Bookstores