+Mount a cloop file:
+
+# aptitude install cloop-src
+# m-a a-i cloop-src
+
+# modprobe cloop file=/path/to/cloop/file
+# mount -r -t iso9660 /dev/cloop /mnt/test
+--
+Create a PS/PDF of a plaintext file:
+
+% a2ps --medium A4dj -E -o output.ps input_file
+% ps2pdf output.ps
+--
+Print two pages on one in a PDF file:
+
+% pdfnup --nup 2x1 input.pdf
+
+Concatenate, extract pages/parts, encrypt/decrypt,
+compress PDFs using 'pdftk'.
+--
+Read a PS/PDF file on console:
+
+% pstotext file.pdf
+
+or on plain framebuffer console in graphical mode:
+
+% pdf2ps file.pdf ; ps2png file.ps file.png ; fbi file.png
+
+or
+
+% fbgs file.pdf
+--
+Bypass the password of a PDF file:
+
+% gs -q -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf input.pdf -c quit
+--
+Record sound:
+
+% rec test.aiff
+
+This will record a AIFF audio file.
+--
+