I finished Coalescent by Stephen Baxter, this evening. Unlike the majority of recent 'hard' scifi (or gosh-wow indistinguishable-from-magic-superscience scifi) I have read, this book centers around biology, evolution and sociology for it's scientific underpinnings. While it took me most of the nine week library renewal cycle to finish it, it was nevertheless quite intriguing. By the time I finished it, I had had that sense of wonder reaction that science fiction is sometimes capable of invoking.
I hear there's a sequel. Perhaps I'll look for it sometime.