I don't know if this is new news, but on one of my newsfeeds this afternoon, the following popped up:
http://appshopper.com/books/bn-ereader
"B&N eReader
Love to read? Always on the go? Now Barnes & Noble, America’s #1 bookstore, makes a world of books as convenient as the iPhone in your hand.
Just download the new, FREE Barnes & Noble eReader app and you can have a great book with you any time, any place.
You’ll have access to over half a million eBooks, including bestselling authors like Stephen King, James Patterson, Dean Koontz, Stephenie Meyer, Charlaine Harris, and more.
..."
It's a free app.
Cheers,
Marc