I prefer real books because they allow me to flick through them. I also think being able to actually feel the book that you hold in your hands adds to enjoyment of reading.
In addition to this, they also keep old-fashioned libraries and bookshops in business. If ebooks ever took over, these places would either have to change or go out of business, and some of them may be run by people who are either technophobic or too old-fashioned to easily learn about them.
Finally, there are probably a lot of great books out there that have not been turned into ebooks yet. Did you know that there is, or at least was, a rumour that the "Harry Potter" books are not on Kindle?