Ethan Marcotte’s “Responsive Web Design” 

Almost as exciting as whatever comes out of today's WWDC announcements: A Book Apart's newest title launches tomorrow, on how web designs can (and should) adapt to the devices used to look at them, rather than force users to pan, scan and zoom their way around a fixed, desktop-oriented layout. I read a preview copy of the book last month, and it's fantastic. The final version coming out tomorrow will be even better; the ePub version will even have videos.