Years ago I put a non-trivial amount of energy into the IP Packet Sniffer tool. There was a "what is happening on my network" thing going on inside my head, driving research into what the Windows OS APIs could give me, and I derived a great deal of fun from the work.
Times change, and although the tool was a great learning experience -- what better way to learn the guts of network protocols than dissecting the bits pulled from the wire -- this tool is way behind serious tools, like Wireshark.
Wireshark is what you should use if you are serious about investigating your network traffic (unless you need something harder core). Wireshark leverages WinPCAP and is therefore far less limited than a raw sockets based method (thanks, Microsoft).
The upshot is that I am freezing work on this tool. I've end-of-lifed a few other tools recently, and removed the download links to those. However, this one still has some life left, if only because it is significantly simpler to start up than Wireshark, so I'll keep making the bits available.
Cheers,
-Eric