I just pre-ordered my copy of Everyware by Adam Greenfield. This is one book I can't wait to read. When I was writing Ambient Findability, All Watched Over by Machines of Loving Grace was truly a source of inspiration.
I haven't found many others who are writing intelligently about the intersection of user experience and ubiquitous computing. I read Mike Kuniavsky's Orange Cone and everything Bruce Sterling writes about blobjects and spime.
So, while we're waiting for Everyware, what else should we be reading?