To take advantage of the MEDIA_URL in the settings.py file for hosting your static media on a separate server, you need to do a
little internal work on your templates and some work to make that setting available to the templates.

Inside a template, where you would normally have:

{{{
blah blah <img src="/img/foo.jpg" alt="this is a foo"> blah blah..
}}}

You would instead insert {{ MEDIA_URL }} so that it would look like:

{{{
blah blah <img src="{{ MEDIA_URL }}/img/foo.jpg" alt="this is a foo"> blah blah..
}}}

It generally requires a big search and replace the first time you implement it. After that, seeing other
references in the templates has been enough to remind me to use {{ MEDIA_URL }} before any static content.

We could pass {{ MEDIA_URL }} in through each view, but since we'll want it throughout the site, it's often easier to
set up a simple context processor to do the heavy lifting.

Note: There is a default media context processor since version 1.0. You can access using {{ MEDIA_URL }} in your templates.

Then in the settings.py under TEMPLATE_CONTEXT_PROCESSORS, add:

{{{
#!python
   "django.core.context_processors.media",
}}}

If you are still on django 0.96:

Here's a example snippet from a context process:

{{{
#!python
from django.conf import settings

def common(request):
    return {'MEDIA_URL': settings.MEDIA_URL}
}}}

Then in the settings.py under TEMPLATE_CONTEXT_PROCESSORS, we added:
{{{
#!python
   "mysite.context_processors.common",
}}}

and from there, the MEDIA_URL in settings.py became available in all templates as {{ MEDIA_URL }}.