I was once in an Apple Store with a failed hard drive when a too-smart-for-his-own-good tech told me: "There are two kinds of hard drives. Those that have failed, and those that are going to."
For better or worse, his sass has stuck with me. The same is true of passwords, especially at the current rate that corporate america is losing our secured information.
You've heard it before, and probably from nerds like me: change your passwords regularly and never use the same password twice.
There's just no way we can be expected to remember $t4rW4RZFAN and change it once a month. The good news, though, is that there's an easy way to create passwords that are easy to change and much, much more difficult to crack.
(The online webcomic XKCD has a great explanation of this: http://ibec.me/QjE3ph)
Amazon.com did this with "PayPhrase" a while back. Make your passwords long by coming up with phrases like "WeLostAKittenInTheWall". It's harder to crack, easier to remember, and a snap to change! You can even select themes for your different passwords (in this case, we'll choose my cat):
No worries if a particular site has imposed restrictions on what characters you have to use -- those can be added as a prefix, like "@88TheCatIsFat".
A couple of simple changes to how you create and manage your passwords can make all of your online accounts much more secure.