cleanup.sh

#!/bin/sh

# delete all linux headers
dpkg --list | awk '{ print $2 }' | grep linux-headers | xargs apt-get -y purge

# this removes specific linux kernels, such as
# linux-image-3.11.0-15-generic but 
# * keeps the current kernel
# * does not touch the virtual packages, e.g.'linux-image-generic', etc.
#
dpkg --list | awk '{ print $2 }' | grep 'linux-image-3.*-generic' | grep -v `uname -r` | xargs apt-get -y purge

# delete linux source
dpkg --list | awk '{ print $2 }' | grep linux-source | xargs apt-get -y purge

# delete development packages
dpkg --list | awk '{ print $2 }' | grep -- '-dev$' | xargs apt-get -y purge

# delete compilers and other development tools
apt-get -y purge cpp gcc g++

# delete X11 libraries
apt-get -y purge libx11-data xauth libxmuu1 libxcb1 libx11-6 libxext6

# delete obsolete networking
apt-get -y purge ppp pppconfig pppoeconf

# delete oddities
apt-get -y purge popularity-contest

apt-get -y autoremove
apt-get -y clean

# free empty space
dd if=/dev/zero of=/EMPTY
rm -f /EMPTY

# run this on your host
# VBoxManage modifyhd --company your-virtual-hd.vmdk