This workflow now password protects chosen PDF files and moves them to the location you specify. The only negative aspect I came across in the process is that by using the Automator action you cannot specify the output file name. If you were thinking that this is done by enabling "Replace existing files" checkbox of the "Move Finder Items" action, you are wrong as this is just a move action. The output file gets a random file name such as pdfauxinfo.k365vaq6.pdf. Quite possibly there is an Automator action that can take the file name and rename it, but I didn't use it.
Accessing password protected PDF files
Opening a newly created password protected file in Preview:
Opening a newly created password protected file in Adobe Reader 8.1.0:
Opening a newly created password protected file in Adobe Reader 8.1.0 on Microsoft Windows Vista:
This is it. A free way of creating password protected PDF files on Mac OS X Tiger.