I just got Norton Personal Firewall 2002, man this software is da bomb, have run several security tests including the one at symantec.com & sygate.com, and NPF2002 blocked ALL attacks.
since getting NPF2002 on Tuesday, I've had 10 backdoor.Trojan attacks, but were all blocked by NPF2002.
It may not be free or cheap, but its well worth every penny.