However, Google introduced Cloud SQL last week and they approved my "Google Cloud SQL" request today (they took 5 days to approve it.:D ). Once they approved, I decided to develop a sample application with Cloud SQL. Gogole Cloud SQL database engine is MySql Version 5.1.59 and database size must be no larger than 10GB. Here I have added option to Test LIKE search. If you need more clarification, feel free to contact me.
Test Application http://securezilla.appspot.
PS: Added Source Code
Sample Project : http://code.google.com/p/cloudsql/
New Post : Google Cloud SQL with Spring and Hibernate
Added on 2011-10-20:
Some people have issue when developing their application because Google currently doesn't support access Google Cloud SQL from outside Google App Engine. there for your local development you need to test with local DataBase(EX: Mysql). After that you when code release to Google App engine it's work fine.
For you local development no need to change the connection URLs.Just need to pass the VM arguments . I think you are using Eclipse IDE.
Go to Run --> Run Configurations
Add the following lines into the your project VM Arguments section.
-Drdbms.server=local -Drdbms.driver=com.mysql.jdbc.Driver -Drdbms.url=jdbc:mysql://localhost:3306/database?user=dbuser&password=dbpass
After that add MySql JDBC driver in to your App Engine SDK/lib/impl folder. Then create DataBase and tables for according to requirement.