Passwords have always been important to get right but with more and more information being put online in publicly accessible locations, such as Google docs, are potential security problems. It's likely someone will know your Google email address if you use Gmail. They are left with just getting the password. That effort could be easy to virtually impossible based on the strength of the password being used.
Password Meter is a free tool that will analyze a password for how strong it is as a password. Finding such a service is not that difficult, but Password Meter goes further to explain what aspects of the password it liked and didn't like.