ColdFusion 8 has a new tag called <cfpdf> which allows
you to merge pdfs. So you can merge pre-created pdfs as well as
pdfs created using cfdocument. Apart from merging, it also allows
you to do whole range of pdf manipulation such as splitting, page
extraction, creating thumbnails, extracing text, creating
watermark, creating table of content, adding/manipulating usage
rights, signing pdf and verifying signature in PDF, extracting
meta-data.