MING Password Spy

From MING Software:

MING Password Spy is an easy to use password sniffer. MING Password Spy allows network administrators or concerned parents to capture passwords of any network users, but such action may be considered as invasion of privacy, and make sure you have the right to do so. Currently MING Password Spy can capture the usernames and passwords of the following Protocols: POP3, SMTP, FTP, Telnet and HTTP (basic authentication passwords). You can use this utility to recover lost Web/FTP/Email/Telnet passwords. It's easy to use, and it can run in stealth mode.