My personal choice, Comodo CIS, is free (not Open-Source) and lightweight on the system. There are many other good ones, some also free (Online Armour has paid and free versions). The only downside to these apps is that they do require some user interaction.

I -hope- so too, only problem is most people who don’t know jack and don’t use antivirus anyways because of the ‘hassle’ involved in it and the complexity of the task just won’t get it, still.

However, many of the whole security software suites that include Firewall, anti-virus, anti-phishing, anti-spyware, etc. protection do include system hooks and such for protecting themselves, and you know what happens? The protection becomes so bloated that it’s as bad as the malware you’re attempting to protect yourself from. Have you tried any of it? It’s really hopeless from the end user perspective. The bad guys will always find a way to subvert the system for their illicit gains until everything is useless. Enjoy.