Creating a password protected ZIP or even DMG can easily be done with the Terminal and a single line of code.
Since it might be a little hustle to write this line correctly I have created two simple webapps that will do it for you!
Create encrypted ZIP
Create DMG with or without encryption
To learn how to use them, click on the “About” link at the bottom of each page.
Feel free to leave comments if there are options missing, or if something is not working properly.