LX Password Generator is a simple password generation form for WordPress by x6g. It can be placed in any page or post.
You can specify which types of characters will be used in the password. Choose from upper and lower letters, digits and special characters to make your passwords impossible to break. All the passwords are generated only within client’s browser session and are not saved anywhere on the server side
Download and info: http://wordpress.org/extend/plugins/lx-password-generator/
Demo: http://lx6g.com/passgen/