Amazon debuts new hosted service called “Amazon Relational Database Service (Amazon RDS)” beta, that makes it easier to set up, operate, and scale a relational database in the cloud. You get direct database access without worrying infrastructure provisioning, software maintenance, or common database management tasks. Using RDS APIs or command-line tools, you can access full capabilities of a MySQL 5.1 database instance. You can scale processing power and storage space as needed with a single API call and you can initiate fully consistent database snapshots at any time. All thats required to build a applications with MySQL will still apply, your code & queries will work as expected, and you can even import a dump file produced by mysqldump to get started. The tiers of service and pricing are:

More info: Amazon blog | Amazon RDS