How to set a Password on Blackberry

How to password protect your Blackberry:

From the Home screen of the BlackBerry smartphone, click Options.

Click Security Options.

Click General Settings. Note: If you are running BlackBerry Device Software 4.0.2 or earlier, click Options, then Security.

Change the Password field to Enabled.

Display the menu and click Save.

Type your new password and click Enter.

Verify your new password by typing it again and click Enter

Thanks to: http://www.berryreview.com/2007/12/26/faq-how-to-password-protect-your-blackberry/