I loved Jacob Kaplan-Moss's "Django Deployment Workshop", which he presented at PyCon and OSCon. In it, he shows how to use cloud servers (he uses the rackspace cloud) to scale multiple web and database servers and do load balancing.

It is a very pragmatic talk, not specific to Django, but suitable for most wsgi setups. It is about 3 hours long.

http://blip.tv/file/3632436