If you're looking for a small, simple, and free password manager, Yadabyte Passwords is the one to get. It's designed as a portable application--that is, it's so small that it fits on a USB flash drive--and it doesn't require real installation. Just unzip the file, run the executable, and that's all you need.
This is about as simple as a program you'll find. You need to enter a master password in order to use it, so that no one else can steal your passwords. Once you do that, you create entries for each of your passwords, including the name of the site, login and password information, and a Web address, if it's a password for a Web site. You can also add notes for any password entry.
Once you do that, view the list of your passwords, double-click any, and you'll get details. Yadabyte Passwords doesn't include features such as automatically filling in Web pages or login screens, so don't expect much beyond the basics. But it's simple and free, and you can carry all your passwords on a USB key, so it makes up for that in simplicity.