How to concatenate PDFs

With GhostScript one can concatenate PDFs without pain: just use the following command line:

gs -q -sPAPERSIZE=a4 -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=newPDFname.pdf PDF1.pdf PDF2.pdf PDF3.pdf

So all the PDFs (PDF1.pdf etc.) are combined in "newPDFname" One can even use a wildcard to combine all the PDFs in a directory by just replacing (PDF1.pdf PDF2.pdf....) with *.pdf