Build a pure Google App Engine environment on your Mac (virtualenv+PIL)

Update: this is unavailable for the current app engine SDK, will occur the cgi import error, the suggestion from experts is "do not use virtual environment with Google App Engine."

1. Install Google App Engine at first (details at http://code.google.com/appengine)
2. sudo port install py25-pil (this will install python2.5 and PIL)
3. virtualenv --python=`python2.5` --no-site-packages appengine
4. enable your virtual environment
5. pip install PIL

that's all.