Install & Configure Headless Dropbox as a Service on Ubuntu 12.04 with this `init.d` script.

dropbox-startup-script

#!/bin/sh

### BEGIN INIT INFO
# Provides:         dropbox service
# Required-Start:   $local_fs $network $remote_fs $syslog
# Required-Stop:    $local_fs $network $remote_fs $syslog
# Default-Start:    2 3 4 5
# Default-Stop:     0 1 6
# X-Interactive:    false
# Short-Desc.:      Start dropboxd at boot time
# Description:      Control dropbox service with the start-stop-daemon
### END INIT INFO

# Users separated by spaces (or no spaces if only 1 user)
DROPBOX_USERS="user1 user2"

# Location of daemon
DAEMON=.dropbox-dist/dropbox

start() {
  echo "Starting dropbox..."
  for dbuser in $DROPBOX_USERS; do
    HOMEDIR=`getent passwd $dbuser | cut -d: -f6`
    if [ -x $HOMEDIR/$DAEMON ]; then
      HOME="$HOMEDIR" start-stop-daemon -b -o -c $dbuser -S -u $dbuser -x $HOMEDIR/$DAEMON
    fi
  done
}

stop() {
  echo "Stopping dropbox..."
  for dbuser in $DROPBOX_USERS; do
    HOMEDIR=`getent passwd $dbuser | cut -d: -f6`
    if [ -x $HOMEDIR/$DAEMON ]; then
      start-stop-daemon -o -c $dbuser -K -u $dbuser -x $HOMEDIR/$DAEMON
    fi
  done
}

status() {
  for dbuser in $DROPBOX_USERS; do
    dbpid=`pgrep -u $dbuser dropbox`
    if [ -z $dbpid ] ; then
      echo "dropboxd for USER $dbuser: not running."
    else
      echo "dropboxd for USER $dbuser: running (pid $dbpid)"
    fi
  done
}

case "$1" in
  start)
    start
    ;;

  stop)
    stop
    ;;

  restart|reload|force-reload)
    stop
    start
    ;;

  status)
    status
    ;;

  *)
    echo "Usage: /etc/init.d/dropbox {start|stop|reload|force-reload|restart|status}"
    exit 1

esac

exit 0