How do I embed PDF files using Acrobat X Pro?

I'm used to using Acrobat 7 to create a PDF and then embed other PDF files within it. I create a link to the embedded PDF using the little paperclip icon so that when the reader double-clicks it, the embedded PDF file opens. Is this still possible in Acrobat X Pro? I'm using the trial version and the only way I can see to do PDF attachments is to have them listed on the left-hand side of the page. I've looked at the help, but it's not helping.