For those of you working with DWF files, you and others on your team can
view and review (e.g. markup) them using Project Freewheel:
http://labs.blogs.com/its_alive_in_the_lab/2008/06/project-freewhe.html
If you add the &mode="ViewOnly" parameter to your Project Freewheel URL,
Project Freewheel will exclude the UI to allow markup. This makes it like
the old DWF Viewer.