Network Analyzer for Windows Mobile was released today as a PowerToy:
Network Analyzer for Windows Mobile runs network utilities, for example ping and ipconfig, on a Windows Mobile powered device. Network Analyzer for Windows Mobile facilitates the troubleshooting of network connectivity issues. You can extend the harness. You can add user-defined tests (DLLs) to the list of tests to be executed. An xml input file defines the list of tests to execute. You can use Network Analyzer to send information about network traffic to a .cap file. You can then view the .cap file with the Network Monitor tool or the Ethereal tool. See the readme file below for more information.
You can download it here.