To the cloud

I'm thinking about building another Android App. 

For this app, I'd like to do some cloud-based things.
1. Sync my user's data to the cloud.
2. Use cloud computing to do some powerful user-specific analysis.

The two most robust options seem to be either Amazon Web Services or Google's Cloud solution.  Here are some points for why Google's App Engine looks good for me.

Cost - "With App Engine, you only pay for what you use. There are no set-up costs and no recurring fees... App Engine costs nothing to get started. All applications can use up to 1 GB of storage and enough CPU and bandwidth to support an efficient app serving around 5 million page views a month, absolutely free."

Handling Users - "APIs for authenticating users and sending email using Google Accounts"

Data storage - Google Cloud SQL provides a relational SQL database service for your App Engine application

Development experience - There is support for development with Eclipse and Java, making it a natural extension to work with my Android Apps.

I'm working through this installation/tutorial now.