Is it possible to create a password-protected archive of a file or folder in OS X? I know about encrypted DMGs, but it seems pointless to have to specify the size ahead of time. A ZIP, RAR, or 7z archive would be better. Example: I work all day on music composition files. At the end of the day I want to archive these files, and I usually e-mail them to myself for backup purposes. However, e-mail is like writing on the electronic bathroom wall, so I want to password-protect these archives. Can one do this in OS X? Right now I'm using Windows (don't hate me - I love OS X too) for my music composition needs, but will probably switch back to a Mac for this task soon. On Windows I currently use the open-source 7-zip program to create password-protected archives. It's funny. I can decompress these archives in OS X, and it prompts me for the password, but I can't figure out how to compress them with a password. Any ideas? I would prefer a free program.