Glasshouse

Another Charles Stross book, I'm enjoying them though so you'll have to bare with me. 
Set in a 27th century future, humanity has spread to the stars through digital technology, humans can be downloaded copied reintergrated etc.  Now if a modern day computer virus is bad what does it do in a completely (more or less) digital unverse?
The story follows an ex-soldier following the end of a war against a computer virus, and his struggle to come to terms with his lack of memory, the reason for that lack, and trying to figure out why someone wants to kill him.
From the outset new ideas are thrown at you, and the implications of them one example the callous disregard for life, cause it's when it's so easy to back yourself up, you can just keep dying.  Or the social implications massivly increased lifespans would have on basic instituitions such as marriage and relaitionships...
Yet it's still an easy to read enjoyable espioage/action romp in a science fiction setting.  Definatly worth a read.