diff --git a/analytical/__init__.py b/analytical/__init__.py
index 1c27423..fff20fb 100644
--- a/analytical/__init__.py
+++ b/analytical/__init__.py
@@ -10,6 +10,6 @@ Django_ project.  See the ``docs`` directory for more information.
 
 __author__ = "Joost Cassee"
 __email__ = "joost@cassee.net"
-__version__ = "0.5.0"
+__version__ = "0.5.1"
 __copyright__ = "Copyright (C) 2011 Joost Cassee"
 __license__ = "MIT License"
diff --git a/analytical/models.py b/analytical/models.py
index e69de29..075c886 100644
--- a/analytical/models.py
+++ b/analytical/models.py
@@ -0,0 +1,5 @@
+"""
+Models for the django-analytical Django application.
+
+This application currently does not use models.
+"""
diff --git a/analytical/templatetags/chartbeat.py b/analytical/templatetags/chartbeat.py
index 5d32db7..b9d4c66 100644
--- a/analytical/templatetags/chartbeat.py
+++ b/analytical/templatetags/chartbeat.py
@@ -58,7 +58,7 @@ def chartbeat_top(parser, token):
 class ChartbeatTopNode(Node):
     def render(self, context):
         if is_internal_ip(context):
-            return disable_html(INIT_CODE, self.name)
+            return disable_html(INIT_CODE, "Chartbeat")
         return INIT_CODE
 
 
@@ -84,12 +84,7 @@ class ChartbeatBottomNode(Node):
 
     def render(self, context):
         config = {'uid': self.user_id}
-        domain = context.get(DOMAIN_CONTEXT_KEY)
-        if domain is None and getattr(settings, 'CHARTBEAT_AUTO_DOMAIN', True):
-            try:
-                domain = Site.objects.get_current().domain
-            except (ImproperlyConfigured, Site.DoesNotExist):
-                pass
+        domain = _get_domain(context)
         if domain is not None:
             config['domain'] = domain
         html = SETUP_CODE % {'config': simplejson.dumps(config)}
@@ -102,3 +97,13 @@ def contribute_to_analytical(add_node):
     ChartbeatBottomNode()  # ensure properly configured
     add_node('head_top', ChartbeatTopNode, 'first')
     add_node('body_bottom', ChartbeatBottomNode, 'last')
+
+
+def _get_domain(context):
+    domain = context.get(DOMAIN_CONTEXT_KEY)
+    if domain is None and getattr(settings, 'CHARTBEAT_AUTO_DOMAIN', True):
+        try:
+            domain = Site.objects.get_current().domain
+        except (ImproperlyConfigured, Site.DoesNotExist): #pylint: disable=E1101
+            pass
+    return domain
diff --git a/analytical/templatetags/performable.py b/analytical/templatetags/performable.py
index 26fc275..f4f027c 100644
--- a/analytical/templatetags/performable.py
+++ b/analytical/templatetags/performable.py
@@ -13,7 +13,9 @@ from analytical.utils import is_internal_ip, disable_html, get_identity, \
 
 
 API_KEY_RE = re.compile(r'^\w{6}$')
-SETUP_CODE = """<script src="//d1nu2rn22elx8m.cloudfront.net/performable/pax/%(api_key)s.js" type="text/javascript"></script>"""
+SETUP_CODE = """
+    <script src="//d1nu2rn22elx8m.cloudfront.net/performable/pax/%(api_key)s.js" type="text/javascript"></script>
+"""
 IDENTIFY_CODE = """
     <script type="text/javascript">
       var _paq = _paq || [];
@@ -69,7 +71,7 @@ def performable_embed(hostname, page_id):
     """
     Include a Performable landing page.
     """
-    return EMBED_CODE % locals()
+    return EMBED_CODE % {'hostname': hostname, 'page_id': page_id}
 
 
 def contribute_to_analytical(add_node):
diff --git a/analytical/utils.py b/analytical/utils.py
index 0ff9f82..9e02ed4 100644
--- a/analytical/utils.py
+++ b/analytical/utils.py
@@ -10,6 +10,12 @@ HTML_COMMENT = "<!-- %(service)s disabled on internal IP " \
 
 
 def get_required_setting(setting, value_re, invalid_msg):
+    """
+    Return a constant from ``django.conf.settings``.  The `setting`
+    argument is the constant name, the `value_re` argument is a regular
+    expression used to validate the setting value and the `invalid_msg`
+    argument is used as exception message if the value is not valid.
+    """
     try:
         value = getattr(settings, setting)
     except AttributeError:
@@ -22,6 +28,12 @@ def get_required_setting(setting, value_re, invalid_msg):
 
 
 def get_identity(context, prefix=None):
+    """
+    Get the identity of a logged in user from a template context.
+
+    The `prefix` argument is used to provide different identities to
+    different analytics services.
+    """
     if prefix is not None:
         try:
             return context['%s_identity' % prefix]
@@ -46,6 +58,13 @@ def get_identity(context, prefix=None):
 
 
 def is_internal_ip(context, prefix=None):
+    """
+    Return whether the visitor is coming from an internal IP address,
+    based on information from the template context.
+
+    The prefix is used to allow different analytics services to have
+    different notions of internal addresses.
+    """
     try:
         request = context['request']
         remote_ip = request.META.get('HTTP_X_FORWARDED_FOR', '')
@@ -63,12 +82,17 @@ def is_internal_ip(context, prefix=None):
             internal_ips = getattr(settings, 'INTERNAL_IPS', '')
 
         return remote_ip in internal_ips
-    except KeyError, AttributeError:
+    except (KeyError, AttributeError):
         return False
 
 
 def disable_html(html, service):
-    return HTML_COMMENT % locals()
+    """
+    Disable HTML code by commenting it out.
+
+    The `service` argument is used to display a friendly message.
+    """
+    return HTML_COMMENT % {'html': html, 'service': service}
 
 
 class AnalyticalException(Exception):
diff --git a/setup.py b/setup.py
index 23bb209..3de7551 100644
--- a/setup.py
+++ b/setup.py
@@ -68,6 +68,6 @@ setup(
     ],
     platforms = ['any'],
     url = 'http://github.com/jcassee/django-analytical',
-    download_url = 'http://github.com/jcassee/django-analytical/archives/master',
+    #download_url = 'http://github.com/jcassee/django-analytical/archives/master',
     cmdclass = cmdclass,
 )