MessenKeep (via)is a freeware application by NirSoft that allows you to hack, crack, decrypt or recover passwords from the following Instant Messenger applications:

-MSN/Windows Live Messenger
-Windows Messenger (In Windows XP)
-Yahoo Messenger (Versions 5.x and 6.x)
-Google Talk
-ICQ Lite 4.x/5.x/2003
-AOL Instant Messenger (only older versions, the password in newer versions of AIM cannot be recovered)
-AOL Instant Messenger/Netscape 7
-Trillian
-Miranda
-GAIM

Since the credentials of an Instant Messenger service is usually the same as your email account, this nifty utility can effectively decrypt and recover your email passwords.

MessenPass works only if you have selected the “Remember Password” option in your instant messenger. When you run MessenPass, it automatically detects the Instant Messenger applications installed on your computer, decrypts the passwords they store, and displays all user name/password pairs found in the main window of the application.

This is a portable application that can be run off a USB device without needing to install it. Therefore, as a safety measure do not select the option to remember the username and password, if possible, on your IM as anybody can anonymously run this tool and get your password.

Download here