a costume with a raspberry pi on battery with a 4Digit 7 segments display that shows a countdown
apt-get install raspi-copies-and-fills python i2c-tools python-smbus
echo "i2c-dev" >> /etc/modules
ln -fs `pwd`/start.sh /etc/init.d/python_clock
update-rc.d python_clock defaults
https://github.com/debian-pi/raspbian-ua-netinst http://skpang.co.uk/blog/archives/575 http://razzpisampler.oreilly.com/ch09.html