She's a Rock'nRoll Ruby! -- Simple IP blocker django middleware.

middleware.py

from django.conf import settings
from django import http

def get_client_ip(request):
    x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
    if x_forwarded_for:
        ip = x_forwarded_for.split(',')[0]
    else:
        ip = request.META.get('REMOTE_ADDR')
    return ip

class BlockedIpMiddleware(object):
    def process_request(self, request):
        if get_client_ip(request) in settings.BLOCKED_IPS:
            return http.HttpResponseForbidden("She's a Rock'nRoll Ruby!")
        return None