Barnes & Noble Inc. has launched an online portal for selling electronic books that currently has over 700,000 titles and is expected to grow to 1 million titles within the next year. This is the latest in a series of developments this summer in the increasingly competitive e-book and e-reader categories. Google recently announced plans to launch a program by the end of the year that will allow consumers to purchase access to digital versions of books via any Web-enabled computer, e-reader or mobile phone. And Amazon.com recently launched the Kindle DX, which is bigger than previous versions.