Over at Thoughts on Code and History, Matt Price has a nice post on Note Taking with PDF Tools and Emacs. PDF Tools is a replacement for DocView but with extended capabilities. Rather than build the PDF image in the file systems, as DocView does, PDF Tools builds it in memory and then allows you to interact with the PDF in various way.
Sadly for those of us in the Cult, PDF Tools is supported only on Linux systems but the README does say that it has been successfully compiled under OS X. The README gives a couple of hints on how to do this. A Stack Exchange question indicates that it's pretty easy to compile and use under OS X so if you're interested it may be worthwhile giving it a try.
I haven't used it yet but will probably try to install it shortly. I don't use Homebrew—the recommended way of installing the tools—so I'll either have to try compiling it by hand or install Homebrew. If anyone has installed it by hand, drop a comment and let me know of any problems or, better yet, lack of any problems.