If you've been waiting for private pinboards to come to Pinterest, then you're in luck because they're finally here! Pinterest is a great blog marketing tool, but it's also a great place for private sharing and team blog collaboration as well as for your personal visual bookmarking needs.
Now you can bring your visual blog content, sharing, and communications to the fastest growing social site by creating secret boards and inviting other users to view the pins on those boards, to pin content to them, and to comment on pins added by other board members.
To create a secret board, just log into your Pinterest account, create a new board and switch the secret setting to the "on" position. To invite people to contribute to your secret board, simply navigate to the "who can pin?" setting for your secret board, enter the name of each person, and click the invite link to add each members
Keep in mind, existing pinboards cannot be changed to secret boards. Only new boards can be configured as secret, and you can create up to three secret boards from a single Pinterest account.
You can follow the link to get more details about secret boards on the Pinterest blog.