Wireshark 1.6.2 Final

Wireshark 1.6.2 Final - Wireshark (formerly Ethereal) is a network protocol analyzer for Unix and Windows. It allows you to examine data from a live network or from a capture file on disk. You can interactively browse the capture data, viewing summary and detail information for each packet. Has several powerful features, including a rich display filter language and the ability to view the reconstructed stream of a TCP session.  

Licence: GPL.
Wireshark 1.6.2 Final

Official site
Downlload: Wireshark 1.6.2 for Windows (21.7 MB)
Download: Wireshark 1.6.2 Portable (16.6 MB)
Download: Wireshark 1.6.2 for other OS