Actually, It should already just work with .pdf's (I used to do this
to get access to my own bibdesk organized list of publications for
grad school. However, the iPhone app itself won't recognize the
filetype at this point (I don't think).
You should know that the server also has beta support for all types of
images (on a mac it can even read your iPhoto library with albums,
etc. much like it does iTunes). Contact me directly ( use
http://help.ootunes.com
) for more info on how to enable this if you're wiling to help report
bugs, etc. since its still very much in beta testing.