I'm now into the third book of the Otherland series (4 books). After a slow start I'm really enjoying it - Williams (
http://www.tadwilliams.com ) has a really good grasp on internet (sub)culture(s) and has extrapolated them convincingly into the future.
If anyone hasn't read his stuff but wants a free taster, there's a few chapters of text free at
http://www.shadowmarch.com - also a good read. I might Subscribe soon...