Vista compatible firewalls

Part of my daily routine consists of visiting online message boards for IT and technical classes for instructing online courses for companies that currently include HP, Sony, Radio Shack, and Motorola (I’ve also taught online courses for Symantec, IBM, Forbes and Business Week, and others). One topic that I’ve built courses for and teach regularly has to do with Windows Firewalls, not to be confused or conflated with the Windows Firewall Program introduced with SP1 on Windows XP, and now included with both Windows XP and Windows Vista.