If you have another application in the same Apache virtual host and also want to use the authentication from Django - this might help. It uses the Django cookie - so it will not work in another Apache virtual host.
If you want to have your wsgi as general as possible (for eg. different environments) without any hardcoded paths, this example might help you...
If you have a production, staging, testing and development environment, you might want to have a global checked in (in your version control system) settings.py for production + a local settings.py to override various settings (like database connection). It's also good for development, since developers don't - by incident - commit to the production settings.py, since they can use their local settings, that should be ignored (.cvsignore, .svnignore or similar).
ofalk has posted 3 snippets.