Index: indico/MaKaC/webinterface/rh/base.py
===================================================================
--- indico/MaKaC/webinterface/rh/base.py	(revision bd21e732ed74b0af04cb323bbcd99ea13048c4bb)
+++ indico/MaKaC/webinterface/rh/base.py	(revision bd21e732ed74b0af04cb323bbcd99ea13048c4bb)
@@ -389,4 +389,15 @@
         return p.display()
 
+    ### SWITCHER
+    def _checkInterfaceSwitchNeeded(self):
+
+        from MaKaC.webinterface.session.base import RequestWrapper
+
+        interface = RequestWrapper(self._req).cookies.get("INDICO_INTERFACE")
+        if interface == 'past':
+            current_url = self._req.construct_url(self._req.unparsed_uri)
+            self._redirect(current_url.replace('indicobeta.cern.ch','indico.cern.ch'))
+    ### ***
+
     def process( self, params ):
         """
@@ -424,4 +435,8 @@
                         self._setSessionUser()
                         self._setLang()
+
+                        ### SWITCHER
+                        self._checkInterfaceSwitchNeeded();
+                        ### ***
 
                         if self._getUser():
Index: indico/MaKaC/webinterface/rh/switchInterface.py
===================================================================
--- indico/MaKaC/webinterface/rh/switchInterface.py	(revision 5d75221cb027333dfd222011edc8cba7295628a2)
+++ indico/MaKaC/webinterface/rh/switchInterface.py	(revision 5d75221cb027333dfd222011edc8cba7295628a2)
@@ -0,0 +1,22 @@
+from MaKaC.webinterface.rh import base
+
+class RHSwitch(base.RH):
+
+    def _checkParams(self, params):
+        self._whereTo = params.get('to','future')
+
+        if self._whereTo not in ['past', 'future']:
+            raise Exception('Unknown value')
+
+        self._returnURL = params.get( "returnURL", "")
+
+    def _process( self ):
+        self._req.headers_out["Set-Cookie"] = "INDICO_INTERFACE=%s; domain=.cern.ch;" % self._whereTo
+
+        url = self._returnURL
+
+        if self._whereTo == 'future':
+            url = url.replace('indico.cern.ch','indicobeta.cern.ch')
+        else:
+            url = url.replace('indicobeta.cern.ch','indico.cern.ch')
+        self._redirect(url)
Index: indico/MaKaC/webinterface/tpls/Header.tpl
===================================================================
--- indico/MaKaC/webinterface/tpls/Header.tpl	(revision 9033fd434a093dfdd0fd4064035868e5535e8d5d)
+++ indico/MaKaC/webinterface/tpls/Header.tpl	(revision 438fbda2c337587a91fbd486e9ce9cd18674a4b1)
@@ -1,4 +1,5 @@
 <% declareTemplate(newTemplateStyle = True) %>
 
+<% includeTpl('InterfaceSwitcher') %>
 <% includeTpl('Announcement') %>
 
Index: indico/MaKaC/webinterface/tpls/InterfaceSwitcher.tpl
===================================================================
--- indico/MaKaC/webinterface/tpls/InterfaceSwitcher.tpl	(revision d000f49af6aa59065c9aabd6771979bb901cb9c3)
+++ indico/MaKaC/webinterface/tpls/InterfaceSwitcher.tpl	(revision d000f49af6aa59065c9aabd6771979bb901cb9c3)
@@ -0,0 +1,10 @@
+<div class="pageOverHeader clearfix">
+<div style="float:right" class="clearfix">
+<a href="http://cerncourier.com/cws/article/cnl/40385">what's new?</a>
+<span style="font-weight: normal; padding-left:5px; padding-right:5px;">|</span>
+<a href="mailto:indico-team@cern.ch">send feedback</a>
+<span style="font-weight: normal; padding-left:5px; padding-right:5px;">|</span>
+<a href="<%= urlHandlers.UHSwitchInterface().getURL('past', returnURL=self._rh.getCurrentURL()) %>">back to old interface</a>
+</div>
+Welcome to the new Indico version!
+</div>
Index: indico/MaKaC/webinterface/urlHandlers.py
===================================================================
--- indico/MaKaC/webinterface/urlHandlers.py	(revision 9f45f3c6d4c9d1397bf48fcb340b855b77ba66cd)
+++ indico/MaKaC/webinterface/urlHandlers.py	(revision 9f45f3c6d4c9d1397bf48fcb340b855b77ba66cd)
@@ -4503,12 +4503,17 @@
         return cls.displayUHs.get("%s%s"%(klazz.__name__, type), None)
 
-# Testing helloworld
-class UHHelloWorld(URLHandler):
-    _relativeURL = "helloWorld.py"
-
-    @classmethod
-    def getURL( cls, name=None ):
+class UHSwitchInterface( URLHandler ):
+    _relativeURL = "switchInterface.py"
+
+    def getURL( cls, whereTo, returnURL="" ):
+        """
+        whereTo - 'future' or 'past'
+        """
         url = cls._getURL()
-        if name != None:
-            url.addParam("name", name)
+        if str(returnURL).strip() == "":
+            url.addParam( "returnURL", UHWelcome.getURL())
+        else:
+            url.addParam( "returnURL", returnURL )
+        url.addParam("to", whereTo)
         return url
+
Index: indico/htdocs/switchInterface.py
===================================================================
--- indico/htdocs/switchInterface.py	(revision 438fbda2c337587a91fbd486e9ce9cd18674a4b1)
+++ indico/htdocs/switchInterface.py	(revision 438fbda2c337587a91fbd486e9ce9cd18674a4b1)
@@ -0,0 +1,4 @@
+from MaKaC.webinterface.rh import switchInterface as rhSwitchInterface
+
+def index(req, **params):
+    return rhSwitchInterface.RHSwitch(req).process(params)