Location: Somewhere, in their fifth dimension...
So I don't know if anyone remembers Peter Watts (he wrote a somewhat mixed review of the show a while back, praising it on an intellectual level whilst criticising its more character-based endeavours), but having read arguably his most well-known book, Blindsight, I think a lot of people here would really like it. Thematically it treads similar waters as the show but goes much deeper into the philosophical quandaries PoI loved to explore, such as consciousness. It even has a great little bit about Turing Tests and their philosophical counterpoint (The Chinese Room).
Anyway, I'd highly recommend it.