Password safe is an open source application that can solve this problem. Instead of remembering hundreds of different passwords, you only have to remember one master password. The rest are encrypted by the program.
Some added benefits of Password Safe are the ability to group your passwords into categories such as home and work, and the ability to generate strong random passwords. You can choose to keep your safe on your hard drive, or you can keep it on a flash drive for added security.
Password safe is incredibly easy to download and install. On the Sourceforge Download page choose the file passwordsafe version 3.17. On the next page, choose the pwsafe-3.17.exe file. (If you are using an operating system other than Windows read the download and installation instructions on the Password Safe Homepage before installing).
After installation, you will be asked to set up a new database. You can save the database on your hard drive, or on a flash drive. Once you choose where to create the database, you will create a safe combination. This will be the only password you will have to remember from now on.
Next you can begin adding your passwords. Ctrl+A will give you a pop up screen. If you click on the Show button next to the password, it will allow you to type the password in clear text.

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Once you have your passwords entered in the database, Password Safe will run quietly in your task bar. When you need a password, click on the icon. You will be asked to type in your master password and then your list will appear. Click on the correct site and the password will be saved in your clipboard. Ctrl+V will allow you to paste it in the password field of the website.
This is just a basic overview of how to use the software. There is a detailed help menu that will walk you through all of the options. There is now no reason not to have secure passwords that will keep your personal information, as well as client information completely private.