I was quite curious to see how facebook applications can be built which use Amazon S3 and Amazon EC2 so I spent some time creating a "HelloWorld" facebook application that lists your Amazon S3 objects given the bucket name (basically integrate Amazon S3 libraries with Facebook libraries). I bundled up my code/configuration and created a Public AMI so that facebook developers can simply re-use my configuration and host their app in Amazon EC2.
AMI ID: ami-74f3161d
AMI Manifest: aws-facebook-app/image.manifest.xml
This Amazon Machine Image is pre-configured and ready-to-go for hosting your Facebook Application. There are some simple steps listed in our Resource Center Public AMIs page that will help you get started.
So now you have solid scalable infrastructure to back you up, innovative facebook platform to play with and all you need is the Killer Idea!
If you think this is helpful, let me know through comments. We could extend this AMI and build an Auto-Scaling module around the app so that we can simply "Auto-Scale Facebook Applications" out of the box and never worry about servers when you get famous overnight.