Install Gimp from Ubuntu PPA

wget https://raw.githubusercontent.com/panticz/installit/master/install.gimp.sh -O - | bash -

#!/bin/bash

# add repository
RELEASE=$(lsb_release -rs | tr -d ".")
if [ ${RELEASE} -ge 1204 ]; then
  sudo add-apt-repository -y ppa:otto-kesselgulasch/gimp
fi

# update
sudo apt-get update -qq

# install gimp
sudo apt-get install -y gimp

# OPTIONAL: enable single window mode
Menu Window > check "Single window mode"

# Links
https://launchpad.net/~matthaeus123/+archive/mrw-gimp-svn - Matt Walker Gimp PPA repository
http://www.webupd8.org/2009/08/how-to-install-gimp-27-in-ubuntu-jaunty.html
ftp://ftp.gimp.org/pub/gimp/v2.7/