Almost all of the books in my tiny apartment are ones I haven't read (yet), or what I consider to be reference books that I keep to look something up in. I have
started collecting some favorite children's books (like picture books), which I intend to keep even though I've read them; that's a bit dangerous. My stacks are embarrassingly high, so I try really hard not to bring any new books home. I guess I'm just a slow reader. I think I've read 7 books so far this year and my mom is on 30 or so.
If I read a book and want to "keep" it, I send it to my parents' house to be stored in my old bedroom. There's a good chance my mom will be interested in reading it too, which helps me feel better about sending them more stuff.
I'm not really into rereading, though; I tend to keep nonfiction more than fiction, in case I want to refer to it, and I keep fiction only if it's really awesome or has some other extenuating circumstance. Basically books have to work it
for me to keep them, it's not the default.
If I read a book and didn't really care for it, I'll get rid of it. I'm not very sentimental about books. Generally I save up several and donate them to the library, or ask a couple of friends if they're interested. Someday I would like to have a big house with lots of room for my books. I still wouldn't keep those I had read and didn't care for, but I would have a lot more room for unread books, reference books, and the few favorites I want to keep forever.
My mom has a Kindle and loves it, and keeps suggesting I get one. I'm not ready to make the leap yet. You know how Amazon recently started saying that if you bought a CD from them, you can download the mp3 songs from that CD for free? I want them to do that with books. You bought this book from us seven years ago--so you can have the Kindle version for free! At least that would take care of some of my stack. I just feel silly getting an e-reader, that I would immediately fill with books, when I have all these unread paper books sitting around. I think right now it would just be an invitation to (further) excess.