There are tons of posts out there showing different solutions, but not always pointing out platforms or with/without virtualenv. This code snippet explains how I got PIL to run in Ubuntu 11.04 using Virtualenv on a EC2 instance, plain and simple.
# Install image libraries
sudo apt-get install libjpeg-dev libjpeg62 libjpeg62-dev zlib1g-dev libfreetype6 libfreetype6-dev
# Install pip
sudo apt-get install python-pip 
# Install virtualenv
sudo pip install virtualenv
# Create virtual env
virtualenv --no-site-packages
# Activate it
source bin/activate
# Run Pillow (a PIL drop-in replacement)
pip install Pillow
Credits: Stackoverflow