Many web sites require you to register with your username and password. How do you keep track of all these registrations? Unless you have exceptional memory you have an option of either user same username and password on each of the sites or keep login details in text document or your email inbox. Both of them are not a secure.

My suggestion is to use one of these two utilities to keep your usernames and passwords.

Password Safe

http://passwordsafe.sourceforge.net/
OS: Windows, Winekeepass
Cost: Free (GPL)

I’ve been using this utility for more than 2 years. It works fine. The only downside is that there is no version for Linux (but it works with Wine) or Pocket PC.

Extract from project website: Password Safe allows you to manage your old passwords and to easily and quickly generate, store, organize, retrieve, and use complex new passwords, using password policies that you control. Once stored, your user names and passwords are just a few clicks away.

Using Password Safe you can organize your passwords using your own customizable references—for example, by user ID, category, web site, or location. You can choose to store all your passwords in a single encrypted master password list (an encrypted password database), or use multiple databases to further organize your passwords (work and home, for example). And with its intuitive interface you will be up and running in minutes.

KeePass Password Safe

http://keepass.info/
OS: Windows
Cost: Free (GPL)

I recently switched to KeePass since where is a KeePassX for Linux. The file format is compatible with KeePass for Windows. Number of third party plugins available, including plugin to import from Password Safe listed above. Pocket PC version is also available.

Extract from project website: KeePass is a free/open-source password manager or safe which helps you to manage your passwords in a secure way. You can put all your passwords in one database, which is locked with one master key or a key-disk. So you only have to remember one single master password or insert the key-disk to unlock the whole database. The databases are encrypted using the best and most secure encryption algorithms currently known (AES and Twofish).