From EJC Cryptography:
iPassMan is a simple utility for managing usernames and passwords for all your online accounts. Incorporating strong encryption with the internationally accepted Advanced Encryption Standard (AES), this program ensures that the security of your details is never compromised.
When you first install iPassMan, you are asked to choose a master password. All accounts you add to the program are automatically encrypted and saved to your computer - the only way anyone can view them is by knowing the master password. Simple.