It doesn't work with all browsers, but this Web password revealer works for Internet Explorer. Functioning without an interface, Password Explorer merely adds a system tray icon that allows you to toggle password detection. The online Help link doesn't go to a Help page. Instead, it just goes to the publisher's site. There's really no user interaction involved other than installing it, though, so the missing user guidance isn't really a big deal.
In many Windows-based programs, including Internet Explorer, asterisk-covered passwords are displayed in seconds. When detection is on, a pop-up appears noting that a password had been detected. Password Explorer issues no alerts when toggled off, but still reveals some passwords.
The app handles only Internet Explorer's autocomplete passwords. It cannot reveal passwords stored on Web sites. Password Explorer is free, so if it reveals just one or two forgotten passwords, you've got your money's worth. If it doesn't work, it's easy to uninstall.