Just a quick note. The PDF security options will NOT prevent people from copying/editing/printing a PDF file. Basically, it all depends on the reader software (and how savvy the user is). Here is a quote from the PDF Reference Third Edition (version 1.4 page 75):

Note: Once the document has been opened and decrypted successfully, the viewer application has access to the entire contents of the document. There is nothing inherent in PDF encryption that enforces the document permissions specified in the encryption dictionary. It is up to the implementors of PDF viewer applications to respect the intent of the document creator by restricting user access to an encrypted PDF file according to the permissions contained in the file.

In other words, I believe there is a patch to ghostview that will make you open and save a read-only PDF file. Also, in the same document (page 77), you'll see a list of the permissions and you can easily give yourself all permissions to a PDF file by modifying these with some editor.

Hope this helps...