Index: applications/mobileblur/controllers/default.py
==================================================================
--- applications/mobileblur/controllers/default.py
+++ applications/mobileblur/controllers/default.py
@@ -17,12 +17,15 @@
     login_form = SQLFORM.factory(
         Field("username", requires=IS_NOT_EMPTY()),
         Field("password", "password", requires=IS_NOT_EMPTY())
     )
     if login_form.accepts(request):
-        results = newsblur.login(login_form.vars["username"], login_form.vars["password"])
-        response.cookies["nb_cookie"] = newsblur.cookies["newsblur_sessionid"]
-        response.cookies["nb_cookie"]["path"] = "/"
-        print "cookie =", newsblur.cookies
-        redirect(URL("index"))
+        try:
+            results = newsblur.login(login_form.vars["username"], login_form.vars["password"])
+            response.cookies["nb_cookie"] = newsblur.cookies["newsblur_sessionid"]
+            response.cookies["nb_cookie"]["path"] = "/"
+            print "cookie =", newsblur.cookies
+            redirect(URL("index"))
+        except Exception as ex:
+            login_form.insert(-1, ex.message)
 
     return dict(login_form=login_form)

Index: applications/mobileblur/modules/newsblur.py
==================================================================
--- applications/mobileblur/modules/newsblur.py
+++ applications/mobileblur/modules/newsblur.py
@@ -24,11 +24,14 @@
         url = nb_url + 'api/login'
         results = requests.post(url, data={"username": username, "password": password})
         print "results.cookies =", results.cookies
         print type(results.cookies)
         self.cookies = results.cookies
-        return simplejson.loads(results.content)
+        results = simplejson.loads(results.content)
+        if results["authenticated"] is False:
+            raise Exception("The newsblur credentials you provided are invalid")
+        return results
 
     def logout(self, ):
         '''
         Logout the currently logged in user.
         '''