Just finished reading an outstanding article on how a hacker could try to steal your information through weak passwords. It was quite compelling, and frightening. I had no idea even adding one capitalized letter and one character could make it exponentially more difficult to hack.
Another thing to keep in mind is that some of the passwords you think matter least actually matter most. For example, some people think that the password to their e-mail box isn't important because "I don't get anything sensitive there." Well, that e-mail box is probably connected to your online banking account. If I can compromise it then I can log into the Bank's Web site and tell it I've forgotten my password to have it e-mailed to me. Now, what were you saying about it not being important?
You have been warned.