The Amazon Web Services (AWS) blog has an entry on using Amazon's Elastic Compute Cloud (EC2) to host and access public data sets, including Ensembl release 51. The data are stored as Amazon Elastic Block Store (Amazon EBS) snapshots. Anyone using EC2 can then create their own EBS using the public data EBS as a starting point. The data are then available to the user to modify, update, and perform calculations using the cloud. You can find more information on how to use the available public data sets and even upload your own data sets at Public Data Sets on AWS.