I just wanted to get some pages out of a bigger PDF file. The tool that can be used for this task is called pdftk. It is in the standard Ubuntu repsitory.
Usage
Split the file, so that every page becomes a new PDF file:
pdftk myfile.pdf burst
Extract pages 10 to 12 from bigPDF.pdf:
pdftk bigPDF.pdf cat 10-12 output output.pdf