I enjoy reading books on my Sony Reader, but, if I have a choice, I like to choose my books by physically holding them. I really like my reader when we are going on trips because I can take lots of books, but they do not take up space or weight up my luggage. But, I still like to go to the bookstore or library and browse the books that they have. I like being able to look at sections that I may not consider if I am looking for books on the computer and looking at the new titles.
When I go to the library, I still come home with a few paper books and sometimes, I jot down titles to find when I get home on my e-reader, either to borrow or buy. More often than not, nowadays, I take pictures of books that I want to read on my cell phone to keep them in mind for later. This happens most often at Target when I have the chance to look at their books. I have found quite a few books browsing here.
Mostly, though, since I am at the library at least once a week, I tend to read paper books as oppose to books on my reader, especially if I am reading professionally. I like to have the references on hand to be able to flag ideas if needed.