Just finished Walter Jon Williams's SF novel, 'Implied Spaces' (A Novel of the Singularity). It's set in a future in which human technology has unprecedented control over reality via vast artificial intelligences (AIs). Using the powers of these AIs people are effectively immortal and can create 'pocket universes'. A war breaks out as a result of an existential crisis in this 'utopia'.

This is another of Williams's extaordinary imaginings - he just keeps getting better and better!

As a change of pace I've just started 'Empires of the Sea: The Final Battle for the Mediterranean, 1521 - 1580' by Roger Crowley. The first couple of chapters are brilliant.