Encrypted backups with Time Machine
If you wish to keep an offsite Time Machine backup in a place which you don’t consider safe (for me it’s my office: although I’m the only one working there, my collegues could in principle get it when I’m out), then this link is for you. It will drive you through the whole process, from creating the encrypted disk image (to an external USB HD, or someplace else), to the Time Machine preference pane configuration.