TraceMyNet is a network tracing tool. It acts as a TCP socket proxy and allows you visualize network traffic, including local traffic that tools like netmon can't capture. It has support for SLL encrypted connections as well. Its main advantage over other tools is the ability to trace local traffic by running as man in the middle and show individual conversations as nodes in a treeview. The data rendering is pluggable so you can write your own parser that understands a specific protocol.
Here are a couple screenshots:
Capture UI:
Options UI:
