Slow River - Nicola Griffith
I'd seen a recommendation somewhere for this book and managed to pick it up through my favourite bookswap site.

Our protagonist, Lore, is the child of a rich family living in a future England - her family has made its money through bioengineering and we first encounter her when she is kidnapped and held for ransom as a teenager. Escaping from her captors, Lore is found naked and battered on the street and 'rescued' by Spanner, a woman who makes her living by hacking and generally doing whatever she needs to do.

Lore is convinced that her family didn't want her back, that the ransom hadn't been paid because of something she had learned, and we see her story in flashback interlaced with her efforts to find a way in this new world in which she is now living, with no legal identity of her own. Lore's relationship with Spanner comes to breaking point and, along with her new endeavours, Lore discovers that some of the things she had believed about her past are anything but true.

I have to say I enjoyed reading Slow River, without even being vexed (as is often the case) by the frequent use of a secondary storyline in flashback to tell us about how Lore got to where she is now. Nicola Griffiths is certainly an author whose name I'll be keeping an eye out for in the future...