Password management has long been one of the most crucial and most complicated tricks to safely and securely pull off. The browser add-on LastPass simplifies it all in a cross-platform tool that's a must-use--as long as you don't mind that it's all in the cloud.
There are several installation options for LastPass. Windows users can run the LastPass universal installer to get the add-on for Firefox, Chrome, and Internet Explorer simultaneously. An extension is available for Opera 11 beta users, but those on Opera 10 will have to settle for the LastPass bookmarklet until the browser's extension network develops catches up. The Windows version of Safari also supports the add-on, but in a separate installer.