I tried to follow a couple of googled up tutorials on setting up mod_python, but failed every time. Do you have a good, step-by step, rock-solid howto?
My dev box is OS X, production - Centos.
There are two main ways of running Python on Apache. The simplest would be to use CGI and write normal Python scripts while the second is using a web framework like Django or Pylons.
Using CGI is straightforward. Make sure your Apache config file has a cgi-bin set up. If not, follow their documentation (http://httpd.apache.org/docs/2.0/howto/cgi.html). At that point all you need to do is place your Python scripts in the cgi-bin directory and the standard output will become the HTTP response. Refer to Python's documentation for further info (https://docs.python.org/library/cgi.html).
If you want to use a web framework you'll need to setup mod_python or FastCGI. These steps are dependent on which framework you want to use. Django provides clear instructions on how to setup mod_python and Django with Apache (http://www.djangoproject.com/documentation/modpython/)