I am looking for examples of pdf files that use reference xobjects.
This is embedding a pdf file(target doc) in another pdf
file(containing doc) and then displaying the target doc in the
containing doc. This is in the pdf spec but I have been unable to find
an example of this to test. I need a link to a sample file or for the
uncompressed source to be posted as the answer or to have the file
sent to me by email.

Have you looked in the PDF Reference Manual?  I'm not sure about
specific examples but it may give you additional information:
http://partners.adobe.com/public/developer/pdf/index_reference.html#5

Yes, I have looked at it extensively. The problem is that there are no
examples of this in the manual. I believe that there are not any
viewers that support it.