Is there a tabbed PDF reader for Mac OS X? I am looking for a tabbed PDF reader, preferably with annotation support (highlighting mostly) for Mac OS X. I looked at the Skim FAQ which said that tabs would never come to Skim.

I am currently writing where I need to have multiple PDFs open for reference (at the moment 17). This is a lot of windows which clutters upp my Exposé.

Does anybody know if such a PDF reader exists for Mac OS X?

I have had a look at Adobe Acrobat Reader, Skim, Preview.app, PDF Pen.

I found Dioretsa which has tabs, but no sadly no annotation.

Update 2015-11-20: Funny how history repeats itself. PDF Expert recently released a Mac version (Readdle's PDF Expert for iOS has been around for some time). The pase years I have been using Preview, but PDF Expert is now my goto PDF reader with tabs and annotation. It's fast as well (which cannot be said about Adobe's PDF products).

Update 2012-05-16: Saving annotations in the PDF itself is also a must. E.g. Skim and Mendeley do not do this. Otherwise, Mendeley would have been a good choice.
Two years later, I may have found something. There is now an app on the Mac App Store called PDF Reader X. It's free, has tabs and supports annotation!