This is easily some of the best sci-fi I've ever read. Stross doesn't just tell an amazing story, he suggests one. The main plot revolves around the growing influence of technology in the main characters lives, and their attempts to figure out where their places in the universe are.

But what most impressed me about this story was the incredibly subtle ducking and weaving necessary to write a story that spans centuries and actively involves exponential growth in technology, without wasting a lot of words to explain the technologies themselves.

Fantastic read.