The Technometria podcast, at ITConversations, has a great episode discussing the architecture of the new Gigavox Audio Lite service. Gigavox Audio Lite is currently in alpha and it is the next generation podcasting platform of Gigavox corporation based on the technology behind ITConversations.
Gigavox‘s engineers made the decision to leverage Amazon‘s infrastructural web services in order to save time and money with Amazon‘s pay per use pricing model. Gigavox‘s case is interesting because they use most of Amazon‘s infrastructural web services and you can see how you can combine the various services to build a complex application. They use S3 for storage, EC2 for batch processing and SQS to connect the the various subsystems. You can see a diagram of the architecture here.