Continuum complements Time Machine, storing up to 10 GB of compressed backups on your choice of off-site storage service: a MobileMe iDisk or Amazon S3 storage bucket. Backups are encrypted with your secret passphrase. You can perform backups manually, or have nightly backups run automatically. Continuum automatically checks for new versions, and keeps itself up-to-date by default. The user interface is designed for simplicity.