Nautilus-Actions installs custom entries in the context menu in nautilus. I needed a simple way to install fonts so I wrote a command for nautilus-actions.

Set "Path:" to bash

Set Parameters to -c "if zenity --question --text=\"Would you like to install the font system wide?\" --title=\"Install to System\"; then gksudo cp %M /usr/share/fonts/truetype/local/%m; else cp %M ~/.fonts/%m; fi; exit 0;".

If you do not want to install nautilus actions you can simply create a Nautilus script.

The contents of the script should be:

#!/bin/bash
if zenity --question --text="Would you like to install the font system wide?" --title="Install to System"; then
     for $i in $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS; do
          gksudo cp $i /usr/share/fonts/truetype/local/$(basename $i)
     done
else
     for $i in $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS; do
          cp $i ~/.fonts/$(basename $i)
     done
fi
exit 0

Save this script in '~/.gnome2/nautilus-scripts' and make it executable (chmod u+x).