The Amazon Web Services cloud portfolio grows yet again with the beta launch of AWS Storage Gateway,  a software appliance designed to connect on-premises applications seamlessly and securely with the Amazon S3 storage cloud.

The idea is to provide a smooth way to back up point-in-time snapshots of application data for backup and disaster recovery purposes by way of iSCSI and other widely supported transfer protocols. The AWS Storage Gateway keeps backup data locally available for low latency, but asynchronously backs it up to the cloud with full AES 256 encryption, according to the official blog entry. And those snapshots are stored as Amazon Elastic Block Store (EBS), which can be used to instantiate new cloud volumes or restored on-premises straight up.

A neat side-benefit is the fact that for moments when you need more capacity, or for remote disaster recovery, or simply to begin taking advantage cloud infrastructure, AWS Storage Gateway lets you mirror your on-premises data into Amazon EC2 instances. Pricing is $125 per activated gateway per month, but with your first activation you get 60 days free to try it out.

As usual, Amazon Web Services has put together an intriguing offering that only enhances the value of its suite as a whole. Now, there are other cloud storage gateway vendors on the market — TwinStrata and StorSimple both make iSCSI a key part of their cloud storage play, for starters. But few other vendors can match Amazon Web Services when it comes to the breadth of its cloud ecosystem.