If you're looking for a great, short, sci-fi I might just have to recommend this one.
Jenna Fox wakes up and has to figure out who she is. She was in an accident, and she's been out of it for about 18 months. Where is the sci-fi? Her dad is the inventor of BioGel (which enables the long term storage of organs, etc.). It makes organ transplants and donations easy. But BioGel makes medical ethics hard.
I couldn't put this one down. I think it was a combination of the very short entries (some are poems, even), the curiosity that is created because of the situation, and the fact that Jenna is smart. She doesn't ignore the clues or sit around waiting for all the pieces to come to her. The book asks awesome questions about ethics and identity and makes you think. . . . Which is why I hated the epilogue. Seriously. Either don't read it, or (if you're like me and wouldn't be able to not read it) wait a couple days before you do. I finished the body of the novel and was like "Wow, cool," and was thinking about all the awesome questions it poses. Then I dove right into the epilogue in which mountains of easy-answers were given. What a disappointment!
So, I liked the book a lot a lot, and the epilogue not at all. I guess that averages out to just one "a lot."
ETA: oh yeah, it's by Mary E. Pearson.