I must admit, I'm a big fan of Google Docs. The features that Google has poored into this offering are simply amazing, whether it's about spreadsheets (which I use most), documents or presentations.
Recently I've discovered that you can use Google Docs also to publish and distribute PDF documents. 
Using this feature is quite easy : simply upload the file and define the collaborators. Done!
Google's technology will take care of the visualization of the PDF file in your browser, which is quite handy. Unfortunately, it's not possible to change the contents of the file, but you can't have it all ...
All in all, Google is starting to put together an offering that becomes more and more competitive in the office and document management space.  More of this !
E.g. : distribute Visio documents?