Listed by Douglas Toombs in WindowsITPro August 2006 issue. They are:
Utilities for Communicating
1. FileZilla
2. OpenSSH
Utilities for Sniffing
3. WinDump
4. Ngrep
5. Ethereal
Utilities for Scanning, Auditing, and Monitoring
6. BareTail
7. NeWT
8. Winfingerprint