UzMSN Shadow beta version is a forensics tool for analysis and digital investigation for the MSN protocol. This tool can perform several active investigation techniques in Microsoft Notification Protocol. It has features such as:

-- MSN text sniffing
-- MSN video sniffing
-- Spoofing messages
-- Hijacking Sessions
-- Shutdown users
-- Save text sniffed in HTML format
-- Save video sniffed in AVI format
-- Reading Pcap dumps

This software depends on QT, libmimic( and libpcap

Download here
Developers Blog

Seems I can't post links yet so just google msnshadow