Amazon Glacier
Amazon Glacier is an extremely low-cost storage service that provides secure and durable storage for data archiving and backup. In order to keep costs low, Amazon Glacier is optimized for data that is infrequently accessed and for which retrieval times of several hours are suitable. With Amazon Glacier, customers can reliably store large or small amounts of data for as little as $0.01 per gigabyte per month…
Amazon Glacier is designed to provide average annual durability of 99.999999999% for an archive. The service redundantly stores data in multiple facilities and on multiple devices within each facility.
Ten dollars a month for a terabyte of safely stored data is a pretty incredible deal and, while Glacier is obviously aimed at businesses and organisations, it looks to be a useful addition to a home backup setup.
The emphasis is firmly on archival storage rather than traditional backup, though: retrieving data from Glacier is, well, glacially slow, expensive relative to storage, and there are even penalties for deleting recently-archived data.
Also of note:
In the coming months, Amazon S3 will introduce an option that will allow customers to seamlessly move data between Amazon S3 and Amazon Glacier based on data lifecycle policies.