Seattle-based Amazon Web Services, the web services arm of Amazon.com, said Monday afternoon that it has released an unlimited, public beta of the firm's database service, Amazon SimpleDB. The SimpleDB service allows any developer of business to easily create a simple database for structured data. The service will work in conjunction with Amazon's other web services, such as Amazon S3 and Amazon EC2, and is priced similarly by machine usage and data transfer. Amazon said that it will provide a free tier of pricing, including 25 machine hours, 1 GB of data transfer, and 1GB of storage at no charge, with additional storage costing $0.25 per gigabyte per month. According to the company, it will soon release a number of features, including ability to create SQL-like queries through an API, and batch API requests.