Manage Your Passwords
Even if you come up with a perfect mnemonic to remember the passwords r[BYX9-5CY@P and b!MO.n5m862T, you may not be able to remember which one provides access to your online banking and which goes with your MobileMe account. You could devise a more elaborate mnemonic device that incorporates some part of the name of the location where each password is used, but a much simpler approach is to let your Mac remember your passwords for you. The easiest (and most secure) way to keep track of a host of passwords is to use a password manager, a program that stores your passwords in an encrypted form and, as a bonus, can fill them in automatically in certain contexts (such as Web forms in compatible browsers).
Tap into Keychain
OS X includes its own reasonably capable password manager: Keychain. Your keychain stores user names, passwords, and other private data in a securely encrypted file. By unlocking your keychain, you gain access to all the passwords inside it, so you have to remember only one.
The Keychain Access application (located in Applications/Utilities) lets you add, remove, view, and edit all your passwords. Your keychain directly supports the Finder, Apple Mail, Apple Safari, and numerous other programs. However, not all applications can use your keychain-Mozilla Firefox, for example, has its own proprietary password manager that other programs can't share.
Keychain is great for simple user names and passwords, but it's less effective when it comes to storing and using other types of data, such as credit card numbers. In many cases, the only way to use such data is to manually copy and paste it between Keychain Access and another application, which is inconvenient at best. For password-management needs that go beyond what Keychain can offer, your best bet is a third-party password manager.
Get a high-powered password manager
Password utilities for OS X fall into two distinct categories: 1Password and everything else. Agile Web Solutions' $40 1Password utility ( Macworld rated 4.5 out of 5 mice ) offers integration with ten different browsers. It stores multiple sets of credentials for a given site, easily handles credit card numbers and other non-password account data, and provides a way to create, enter, and save a new password with a grand total of two clicks. It's also available as an iPhone app ( Macworld rated 3.5 out of 5 mice ) that syncs all your passwords with your Mac. Other utilities, whatever their virtues, are far less convenient and versatile. So I recommend using 1Password for credentials you must enter in Web browsers, and Keychain for credentials used by OS X components such as file and screen sharing, AirPort networks, and Mail accounts.(Image Caption: 1Password lets you store multiple sets of credentials for each domain, and gives you access to most of its functions through a pop-up menu right in your favorite browser.)
Because password utilities can create, remember, and fill in passwords for you, they spare you a considerable amount of mental effort. Plus they keep you more secure by increasing the odds that you'll select a different, random (or nearly random) password each time you need to create one. In addition, 1Password lets you carry all your passwords with you, securely, on your iPhone or iPod touch. It can optionally export your passwords as plain text, so you need not worry that you'll be stuck without your passwords if some hypothetical Apple software update breaks 1Password or if the product disappears.