So I've been reading on my smartphone, substituting reading free ebooks for my old favorite vices of sudoku and crossword puzzles. I really enjoyed Secret Adversary (by Agatha Christie - a Tommy and Tuppence!) and Twenty Thousand Leagues Under the Sea, which I hadn't read in ages and had totally forgotten. But one of my favorite books, Notes from the Underground, was a little frustrating to read on a three-inch screen so I gave up and dug it off my bookshelf to finish. I think that phone reading is better suited for less complex reading or at least shorter sentences, as it's tough to focus when flipping the pages so frequently, something a bigger screen would help. I can't imagine how horrible it would be to read Henry James on a phone - it would take three screens per phrase.
If I could read in the bathtub with one, I might buy an eReader device of some sort (especially for magazines and journal articles - I print out way too many pdfs). But I think I am too attached to paper books to ever really change over. I like to lend books, to give them away, to browse through piles of them, to acquire them on curbs from dejected little heaps. I still remember plunking down my Christmas money to buy my first book on my own. It was a paperback copy of Charlie and the Chocolate Factory and I read it 28 times in a row, memorized it, and eventually made a replacement cover for it out of gold foil and candy-wrappers.