Dependencies:

# Install Macports

Goto http://www.macports.org/install.php

# Install Python and the necessary dependencies for Django + Google App Engine

sudo port install openssl python25 python_select py25-socket-ssl py25-pil py25-setuptools
sudo python_select python25
sudo ln -s easy_install-2.5 /opt/local/bin/easy_install

# Install Django

cd /tmp
wget http://www.djangoproject.com/download/1.0-beta-1/tarball/ -O Django-1.0-beta-1.tar.gz
tar zxf Django-1.0-beta-1.tar.gz
cd Django-1.0-beta_1
sudo python setup.py install
cd /tmp
sudo rm -rf Django-1.0-beta*

# Install Google App Engine

* Browse and download from http://code.google.com/appengine/downloads.html
* Drag GoogleAppEngineLauncher into your Applications folder, and launch it.
* Enter your password to install the necessary files.

# Run the server

cd appengine
./manage.py runserver

.h2 Getting this exception?

django.core.exceptions.ImproperlyConfigured: 'appengine' isn't an available database backend. Available options are: 'ado_mssql', 'dummy', 'mysql', 'mysql_old', 'oracle', 'postgresql', 'postgresql_psycopg2', 'sqlite3'

Try this:
  
  ln -s /opt/local/lib/python2.5/site-packages/django django

You can access a Google App admin page here;

http://localhost:8000/_ah/admin