BlackBook by mblware
If you're looking for a way to keep your BlackBerry contacts and related activities away from prying eyes, you'll be happy to hear that BlackBook by Mblware has recently been updated to v4, bringing with it several new features and improvements. The app is now compatible with BlackBerry 7 devices, is faster than ever, and the look has been revamped. Additions include multiple email addresses for contacts, user pics in the contact list, and HTML email is now supported as well. If you are an existing BlackBook user, you can update to the latest version for $.99. Full price of the application is $3.99.

More information/details and to purchase BlackBook from the CrackBerry store
More information/details and to purchase BlackBook from App World