I'm not around much, and I may have missed a post on this book, but I just stumbled on it in our local library, and it deserves a look. It's called "The Laws Field Guide to the Sierra Nevada."
It's written and illustrated by John Muir Laws (published 2007 by Heyday Books). It's sturdy and portable and thorough and absolutely beautiful. It sure does set the bar high though; if I saw even a tenth of this stuff during a lifetime in the bush, I'd die a happy man.