Arq 3 (the killer Mac utility app that backs up your files and folders to Amazon S3) shipped about a week ago, and it now supports Amazon Glacier.
For my off-site backups I use both Arq and BackBlaze. I don’t have enough data to be worth it for me to use Amazon Glacier (my monthly S3 bill for Arq backups is less than $8). But for those who do have a whole lot of data which you don’t expect to ever need to recover except in the worst case scenarios, then using Amazon Glacier may be just right for you — it’s cheap to upload and cheap to store, but can get expensive when you need to recover that data.