Is this the beginning of the end?

Oh dear.  I've bought an e-reader.  It doesn't smell like a book, and it doesn't have that lovely dense feeling of a book, but it fits into my hand luggage so much more easily.  Now I have to decide whether the books I buy for it are just those I don't mind not having in solid form, or perhaps a digital version of a favourite so I can read it again, or what?  What do I do if I read an e-book that I love and want to keep?  I clearly have a l-o-n-g way to go before really accepting this format, but I've put my toe in the water.  I suppose if I fall in love with a book and HAVE to have it on my real shelves as well as my digital ones, I may just have to buy it twice.