The guy that said "firewall is only for n00bs" is an idiot, and is plain wrong. And incidentally, so is the original poster for recommending that people uninstall their software firewalls and plug their computers directly into the modem.
You just don't put a production box directly to the Internet. Even if
you're 100% sure you don't have any exposed services at all (which is way out of league for anyone inexperienced enough to be needing the guy's tutorial in the first place), you still have protocol stack bugs to consider, kernel bugs, etc. You don't plug a production box directly to the Internet without something in between, at the very least a software firewall and ideally that plus a standalone firewall.
It is irresponsable - to say the least - to be recommending to anyone that they disable their firewalls and plug their computers directly to the net, more so when the people who are targeted by this recommendation are just about inexperienced enough (and desperate to download the latest Paris p0rn or whatnot) to do it. You're helping the armies of zombiefied computers increase in number, you're harming your own users by telling them to leave their computers unprotected.
Have you any idea how long it takes on average for an out-of-the-box Windows XP computer to get infected by some worm or the likes after you plug it to the Internet? Well let's just say it's measured in seconds (and yes that means it's under a minute).
Instead of telling people to irrationaly expose their computer to damage for the sake of getting a few more Kb/s out of some warez download, you should be telling them how to configure
their firewalls to allow port forwarding. Really, it's not rocket science, and it the concept's been around for far far longer than BitTornado or BitTorrent.
And by the way, the guy that said firewalls can stop viruses is an idiot too. So now a firewall prevents an exe from writing to another exe? Or from playing with your screen, or infecting your mbr, hell even from formatting your partitions? And a firewall can stop hackers? You need to know what a hacker is first, before thinking you need to be stoping them from anything. A hacker is not a criminal
. A hacker is someone who excels at something, e.g. programming, networking, etc. Don't confuse crackers and wannabe spoiled brats that download some tool and click on the little red button that says "0wn teh l0053r" without even knowing how it works.