you can make some programming inside the pdf file in order to hide it when openning, or you can point to an html page instead. in this html page, embed an obejct tag and in that make a link to the pdf file passing a parameter in the string... something like my:doc.pdf?toolbar=0.
Please google about this and you will find what Im trying to explain.
Finally, note that you can hide it, but users can always show it again pressing ..F4 I think (or other key... I dont have sure what key ).