IP sniffer 1.53 has been released couple days ago. Very nice and small (680kb) and absolutely FREE.
Description:
IP sniffer is a protocol analyzer, that uses the XP/2K Raw Socket features. It supports filtering rules, adapter selection, packet decoding, advanced protocol description and more. Detailed information about each packet is provided in a tree-style view, and the right-click menu allows to resolve or scan the selected source IP address. Additional features include adapter statistics, IP traffic monitoring, traceroute, ping, port scanning and TCP/UDP/ICMP spoofing options.
Link: http://www.snapfiles.com/get/ipsniffer.html
