It is no secret that google has been working on a host of web services that will compete directly with Amazon Web Services. These web services are made for hosting applications that grow to very large sizes (if the application takes off that is). The users get 500mb of storage for free which is a decent start. When you combine app engine with Open Social you have the ability to use App Engine as a hosting service for applications that can be used in social networking sites. I would recommend you check out their App Engine Gallery to see some of the benefits of using the platform. One potential weakness is it’s lack of PHP support but I can’t imagine they won’t implement PHP support soon enough. Although that is not really a huge deal if anything it is an excuse to learn something new. If you haven’t looked at PureMVC now you have an opportunity to use it. You can go to their website read up on it and look at their examples here is a blog that uses PureMVC python on App Engine. If you do not wish to use PureMVC you could always go with Django. Both of these technologies utilize the Model View Control design pattern if you are not familiar with that design pattern I advise looking into it.