This isn't directed at the parent... This is directed at bimbom.
There are and will be viruses for any platform. That's just part of it. What makes Linux different is, that a vast majority of Linux users aren't going to download some free screensaver, or some free card came, etc... Why? Either they already have it by default, or there is a free, open source, trusted alternative. Even if you did download a binary on accident, and accidentally 'clicked on it', guess what happens. Nothing, unless your filemanager automatically makes it executable, and automatically executes it. You might start looking for a better file manager when that happens.
The idea of Linux virus is nothing like that of Windows, and the idea of a Linux worm is just hillarious. Give two Linux users cloned HDs in two identical boxes. Come back in 2 months, and you'll notice something. Their systems are completely different. They will most likely be using two completely different web browsers, different mail clients, different everything. When you use Linux, you have a choice. You aren't forced to use explorer.exe.
If you wanted to write a Linux 'virus' you would have to attack something common to all Linux boxes... bash, xorg, the kernel, gnu-utils, etc... These are all far too mature to be attackable by the random script kiddie. Linux is open. If somebody finds a hole, it's plugged. If you choose to run closed source software on Linux, fine, so be it. I just pray that it's mature, and not running as a server on the internet side. The biggest threat to Linux, in my opinion, is having a weak password, and leaving SSHD running if you don't use it. And don't forget the dumb user. And in this case, all that should happen is that either you get rootkitted (very very rare), or that users files get deleted. Don't allow root to login remotely. That's retarded. Don't even allow your user to login remotely, make a user that you use for remote work. You can su to your primary account from there.
Your average Linux user is much more saavy than your average Windows user. It's two different worlds, don't even try to compare. Linux is not Windows.
Linux is being used on corporate firewalls, massive DNS servers, large websites, space shuttles, satellites, navigation systems, etc... And guess what. Without antivirus. In reality, you 'could' run Windows with no antivirus. I've done it. Use a good hardware firewall, make sure other machines on your network are seperated, or similarly protected, and don't run every damn exe you come across.
Guess what. I put a Linux box on a Windows network, and enabled Samba, and setup a default, wide open share, similar to that a Windows user would have. Guess what happened? That samba share was filled with random exes with catchy names. What happened after that? Nothing! They were all the same exact file, just a different name. I actually, ran one with Wine, Cedega, and Crossover for fun. Guess what happened... Nothing! Guess what happened to the Windows boxes. RPC crashed and forced a reboot. I'm sure you know what worm I speak of. You know what happened next? Those Windows boxes tried to phone home to an IRC server. What happened then? My Linux firewall blocked it. Now my Linux firewall/router runs antivirus and a spam filter. Not a single Windows machine in my office runs antivirus, or a firewall, or a spam filter. And you know what? We don't get viruses, worms, spam, or any of the other cruft that plauges other networks.
That Linux antivirus checks for Windows viruses, not Linux. No viruses/worms in, no viruses/worms out, no viruses/worms between machines. I've infected a box on purpose with as many worms and viruses as I could get my hands on, and it didn't spread.
Linux is not Windows.