Hi Folks,
Thanks for all the suggestions. I got it working by doing the following.
1. downloaded the script (thanks whpalmer4) AddFileToInbox from the link
http://www.cerquant.com/omnifocus_scripts
2. Moved the scripts to a directory where I would keep it, and created an alias to "AddFileToInbox_Dropplet" (right click on it and choose "create alias").
3. Then I moved the alias to the folder "~/Library/PDF Services", and changed the alias name to "Save PDF to Omnifocus".
That's it. Not I can print a pdf to Omnifocus.
Now, there is a small caveat. For some reason, when I print it, the file is saved in a subdirectory of /private/var/folders/.../tmp, which suggests me is a temporary directory. Do you guys know if there is a way to change this?
Thanks again for all the help.
Acacio