With regards to e-readers:
I have a Sony e-reader and it has completely changed the way I read. First off, the screen is incredible, exactly like I was reading from a real page. Books are less expensive (or free through google) and I no longer need to wait til I have time to go to the bookstore to get a new book.
Furthermore, you don't even have to use Sony's software, so there's no real licensing risk. In regards to sharing books, my friend also has one, so I can at least share with him : )
The best part is probably the sheer number of books it can fit. I'm currently reading a series that has five books in it. The other day, I was on the bus, finished one book, and could just start another. Also, sometimes in the middle of reading, I feel like reading a short story, and I just switch to an anthology that would be impossible to carry around everywhere.