Take rotating Amazon AWS EBS snapshots with this small node.js script.
See setting.json for sample definitions. Options include:
pool - the number of snapshots to maintain before destroying old ones. device - name of device that should be snapshotted. description - used as the description for the snapshot along with the device name and the instance ID.
node index.js --config=settings.json ... throw that in a hourly, daily, etc. cronjob and set the 'pool' size and you've got rotating snapshots.