xkcd’s advice on creating memorable passwords
xkcd comic offers some helpful advice on creating memorable but still difficult to hack/guess passwords.

“Through 20 years of effort, we’ve successfully trained everyone to use passwords that are hard for humans to remember, but easy for computers to guess.”
Take a lesson: a password of four random words is harder to guess but easier to remember than a one-word password containing some gibberish symbols substituting for letters.
Source: xkcd: Password Strength