TCP Spy .NET is a small application used to trace TCP packets
between a client and a server. Optimized for.Net Web Services or
Web Site TCP Spy .NET will help you find any bottleneck and it
will help you in analyzing your bandwidth usage. With TCP Spy
.NET, you can inspect data in different views, track server calls
or just redirect the host.

It's a 4 in 1 tool:
* monitoring tool
* web service / web site profiling tool
* redirection server
* Network / Web Site / Web Services spy