Saturn's Children - Stross

(This is another nominee for this year's Hugo for Best Novel.)

Back in the 40's, Isaac Asimov created the Laws of Robotics. There are three laws and they're designed to make certain that robots serve humanity and strive to never injure them. Asimov used the laws to make an entertaining set of short stories that look at how these laws effect interaction between men and robots.
Stross has created a world (set a few centuries in the future) in which robots are commonplace and mankind has somehow become extinct (the details are fuzzy on this). The book is told from the viewpoint of an escort android. She misses humanity and whenever she comes across a lifelike replica she becomes weak in the knees from her programmed desire.
'Saturn's Children' is also a fairly involved tribute to the Heinlein novel 'Friday'. Many of the details are obviously nods to the earlier book. If you liked 'Friday' (and I certainly did) this book will give you plenty of warm fuzzies.
Another interesting aspect of the book is that Stross writes with slow interplanetary travel. As the characters move from planet to planet the trips take months and years to complete. Each trip has somewhat different methods and the results are facsinating.
The plot is complex and purposefully confusing. The tone is somewhat noirish and very well done. Overall it's a very good book.