password protect archive?

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.

 

To answer my own question, the only application I have found that can do this (for free) is Ez 7z.

It's ugly, but it works for now. It is basically a front-end for p7zip, and it has to fire up the Terminal to work.

The application 7zX looks promising, but (to my knowledge) cannot encrypt archives with a password. I've made a request for this option on the developer's site.

Am I so strange in my desire to easily create password-protected archives? To me this seems like a very common thing to do, and there are several free Windows applications that can do this. I'm baffled as to why there are not yet equivalents for OS X.