diff --git a/symposion/boxes/urls.py b/symposion/boxes/urls.py
index c0cf3fb1..993ec136 100644
--- a/symposion/boxes/urls.py
+++ b/symposion/boxes/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import url, patterns
+from django.conf.urls import url, patterns
 
 
 urlpatterns = patterns("symposion.boxes.views",
diff --git a/symposion/cms/urls.py b/symposion/cms/urls.py
index be16e2cd..74064edb 100644
--- a/symposion/cms/urls.py
+++ b/symposion/cms/urls.py
@@ -1,5 +1,5 @@
-# flake8: noqa
-from django.conf.urls.defaults import url, patterns
+from django.conf.urls import url, patterns
+
 
 PAGE_RE = r"(([\w-]{1,})(/[\w-]{1,})*)/"
 
diff --git a/symposion/conference/urls.py b/symposion/conference/urls.py
index f2cdd52b..90ae79f8 100644
--- a/symposion/conference/urls.py
+++ b/symposion/conference/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import patterns, url
+from django.conf.urls import patterns, url
 
 
 urlpatterns = patterns("symposion.conference.views",
diff --git a/symposion/proposals/models.py b/symposion/proposals/models.py
index c12c5bcc..699f70b6 100644
--- a/symposion/proposals/models.py
+++ b/symposion/proposals/models.py
@@ -1,4 +1,3 @@
-import datetime
 import os
 import uuid
 
@@ -6,6 +5,7 @@ from django.core.urlresolvers import reverse
 from django.db import models
 from django.db.models import Q
 from django.utils.translation import ugettext_lazy as _
+from django.utils.timezone import now
 
 from django.contrib.auth.models import User
 
@@ -37,20 +37,18 @@ class ProposalSection(models.Model):
 
     @classmethod
     def available(cls):
-        now = datetime.datetime.now()
         return cls._default_manager.filter(
-            Q(start__lt=now) | Q(start=None),
-            Q(end__gt=now) | Q(end=None),
+            Q(start__lt=now()) | Q(start=None),
+            Q(end__gt=now()) | Q(end=None),
             Q(closed=False) | Q(closed=None),
         )
 
     def is_available(self):
         if self.closed:
             return False
-        now = datetime.datetime.now()
-        if self.start and self.start > now:
+        if self.start and self.start > now():
             return False
-        if self.end and self.end < now:
+        if self.end and self.end < now():
             return False
         return True
 
@@ -102,7 +100,7 @@ class ProposalBase(models.Model):
                     "target='_blank'>Markdown</a>.")
     )
     submitted = models.DateTimeField(
-        default=datetime.datetime.now,
+        default=now,
         editable=False,
     )
     speaker = models.ForeignKey("speakers.Speaker", related_name="proposals")
@@ -175,7 +173,8 @@ class SupportingDocument(models.Model):
     proposal = models.ForeignKey(ProposalBase, related_name="supporting_documents")
 
     uploaded_by = models.ForeignKey(User)
-    created_at = models.DateTimeField(default=datetime.datetime.now)
+
+    created_at = models.DateTimeField(default=now)
 
     file = models.FileField(upload_to=uuid_filename)
     description = models.CharField(max_length=140)
diff --git a/symposion/proposals/urls.py b/symposion/proposals/urls.py
index c2efdcb5..a69e6136 100644
--- a/symposion/proposals/urls.py
+++ b/symposion/proposals/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import *
+from django.conf.urls import patterns, url
 
 
 urlpatterns = patterns("symposion.proposals.views",
diff --git a/symposion/proposals/views.py b/symposion/proposals/views.py
index b3a3edfe..570e988b 100644
--- a/symposion/proposals/views.py
+++ b/symposion/proposals/views.py
@@ -7,7 +7,12 @@ from django.core.urlresolvers import reverse
 from django.db.models import Q
 from django.http import Http404, HttpResponse, HttpResponseForbidden
 from django.shortcuts import render, redirect, get_object_or_404
-from django.utils.hashcompat import sha_constructor
+
+try:
+    from hashlib import sha1 as sha_constructor
+except ImportError:
+    from django.utils.hashcompat import sha_constructor
+
 from django.views import static
 
 from django.contrib import messages
diff --git a/symposion/reviews/urls.py b/symposion/reviews/urls.py
index 3cdc6f73..1719eb0e 100644
--- a/symposion/reviews/urls.py
+++ b/symposion/reviews/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import patterns, url
+from django.conf.urls import patterns, url
 
 
 urlpatterns = patterns("symposion.reviews.views",
diff --git a/symposion/schedule/models.py b/symposion/schedule/models.py
index a47afb9d..5954e07e 100644
--- a/symposion/schedule/models.py
+++ b/symposion/schedule/models.py
@@ -80,8 +80,9 @@ class Slot(models.Model):
         Unassign the associated content with this slot.
         """
         if self.content and self.content.slot_id:
-            self.content.slot = None
-            self.content.save()
+            presentation = self.content
+            presentation.slot = None
+            presentation.save()
 
     @property
     def content(self):
diff --git a/symposion/schedule/urls.py b/symposion/schedule/urls.py
index 94acd3e1..b6cd1630 100644
--- a/symposion/schedule/urls.py
+++ b/symposion/schedule/urls.py
@@ -1,5 +1,5 @@
-# flake8: noqa
-from django.conf.urls.defaults import url, patterns
+from django.conf.urls import url, patterns
+
 
 urlpatterns = patterns("symposion.schedule.views",
     url(r"^$", "schedule_conference", name="schedule_conference"),
diff --git a/symposion/speakers/urls.py b/symposion/speakers/urls.py
index 0d1c7b13..fb30e787 100644
--- a/symposion/speakers/urls.py
+++ b/symposion/speakers/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import *
+from django.conf.urls import patterns, url
 
 
 urlpatterns = patterns("symposion.speakers.views",
diff --git a/symposion/sponsorship/urls.py b/symposion/sponsorship/urls.py
index e6ba5fa3..c7dc581c 100644
--- a/symposion/sponsorship/urls.py
+++ b/symposion/sponsorship/urls.py
@@ -1,10 +1,9 @@
-# flake8: noqa
-from django.conf.urls.defaults import patterns, url
-from django.views.generic.simple import direct_to_template
+from django.conf.urls import patterns, url
+from django.views.generic import TemplateView
 
 
 urlpatterns = patterns("symposion.sponsorship.views",
-    url(r"^$", direct_to_template, {"template": "sponsorship/list.html"}, name="sponsor_list"),
+    url(r"^$", TemplateView.as_view(template_name="sponsorship/list.html"), name="sponsor_list"),
     url(r"^apply/$", "sponsor_apply", name="sponsor_apply"),
     url(r"^add/$", "sponsor_add", name="sponsor_add"),
     url(r"^(?P<pk>\d+)/$", "sponsor_detail", name="sponsor_detail"),
diff --git a/symposion/teams/urls.py b/symposion/teams/urls.py
index d70a600d..785c4300 100644
--- a/symposion/teams/urls.py
+++ b/symposion/teams/urls.py
@@ -1,5 +1,4 @@
-# flake8: noqa
-from django.conf.urls.defaults import *
+from django.conf.urls import patterns, url
 
 
 urlpatterns = patterns("symposion.teams.views",