Using the same password for multiple accounts is extremely bad security practice. There are software programs for mobile and fixed platforms that will allow you to manage multiple passwords--some even generate random-passwords for you that you will never have to remember. In 2011, there is no excuse for using the same password on more than one site. If you're compromised on one, you're an easy target on the others.

How do criminals break passwords? Often, through "brute-force": a computerized program runs through possible combinations until it cracks your password. And of course, it starts with the most common ones, which are invariably weak.