Do you have a friend, sibling, spouse, or other person who has access to your BlackBerry? If so, you might want to hide information. Even if not, you might want to keep things out of public view, just in case you lose the device or it is stolen. We’ve discussed deleting a contact from your call history, but sometimes that’s not enough. Wouldn’t you like a secret address book, one you can hide from prying eyes? Via BlackBerry Cool we learn of one: BlackBook. It’s a cheap application which creates a new, secret address book which only you can access. To ensure the security of your private contacts list, BlackBook requires you to set a key combination in order to access the list. This you can set in the application’s options menu. To access BlackBook after activation, you’ll hit the End button five times on the Home Screen. This way, only those who know your secret key combination — that is, only you — will be able to access the book. The address book fields are a bit more stripped down than the normal BlackBerry address book, but that shouldn’t be a problem for most. No reason to keep too much information on your Berry about this contact if he or she is to be secret. Best of all, in my opinion, is the ability to set up custom filters for calls and messages from these contacts. This way you can keep the messages from your main inbox, again keeping them from private eyes. You can also set custom tags for caller ID, so that the name in your contact might not appear when he or she is calling. It’s yet another level of protection. You can get BlackBook at the BBGeeks Store for $3.99. That’s a small price to pay for unprecedented BlackBerry privacy.