Presence is a new sci-fi novel from Richard MacManus, founder of the huge ReadWrite tech blog, and it's also inspired by Second Life and other virtual worlds:
"The book is set in 2051," he tells me, "when the dominant social network of the era is a virtual world called Doppel. I wanted to explore what a Facebook 35 years into the future would look like. My bet is that it'll be a virtual world, kind of like what Second Life is these days for socializing and doing business. Except in Doppel, your avatar is an exact match of your physical body. The technology is so good in 2051, that you can easily jump between the physical and virtual worlds without noticing much difference."
I'm hoping to read it when I get the chance, and if you're an SL blogger interested in reading it too, Richard has a generous offer: