+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.
+--
+Change passphrase / password of an existing SSH key:
+
+% ssh-keygen -p
+--
+Enable syntax highlighting in nano:
+
+Just uncomment the include directives for your respective
+language at the bottom of the file /etc/nanorc
+--
+Create netboot package for grml-terminalserver:
+
+# sh /usr/share/doc/grml-terminalserver/examples/create-netboot
+--
+Rotate pictures:
+
+Using the 'Orientation' tag of the Exif header, rotate
+the image so that it is upright:
+% jhead -autorot *.jpg
+
+Manually rotate a picture:
+% convert -rotate 270 input.jpg output.jpg
+--
+Rename files based on the information inside their exif header:
+
+% jhead -n%Y-%m-%d_%Hh%M_%f *.jpg
+
+This will rename a file named img_2071.jpg to something like:
+
+2007-08-17_10h38_img_2071.jpg
+
+if it was shot at 10:38 o'clock on 2007-08-17 (according to
+the information inside the exif header).
+--