OT how to merge pdf's or ps files

[kevin.kempter at dataintellect.com]

Hi List ;

I have needs to merge a gnucash invoice which I can print to file as a .ps 
(postscript file) and then use ps2pdf to create a pdf with a spreadsheet for 
expenses and images of the receipts.  I would like to push all this into a 
single multi-page PDF to submit to my client for payment. Any ideas on how to 
pull this off?