When you create a django project, it automatically creates a settings.py file. Put your settings in that file, and then :-
from django.conf import settings  
settings.YOUR_SETTING
also, if you have some settings, that will vary depending upon the machines (eg. production/test servers).
Then just add eg. conf/local_settings.py file and put the machine specific settings in that file, and in settings.py just do :-
from conf.local_settings import *
at the end of settings.py
Make sure you ignore local_settings.py from your VCS check-in (eg. in case of git add local_settings.py to .gitignore