Does a Mac need anti-virus protection?

Above: Apple Mac malware: caught on camera

I've just switched to a MacBook Pro running Snow Leopard.
I was offered McAfee's anti-virus software but I've been advised by 
Mac users and Apple support that I do not need either anti-virus 
or anti-malware software running. Is that true?

Jerome Goldstein
I don't know of any live malware attacking Mac OS X, so you probably don't
need either anti-virus or anti-malware software at the moment. However, this
does not mean you shouldn't run it. If you are a home user, you don't have to
care what happens to your data, but business users do. It may be wise to take
precautions, even if they don't appear to be necessary.

People should also think about protecting their computers if they are a
particularly attractive target for some reason. The Mac is not short of security
flaws, and security consultant Nitesh Dhanjani recently commented to CNet that
"the Safari web browser also has a lousy reputation in the security community --
it almost seems a child's play to locate an exploitable condition in Safari."
The fact that there are no mass exploits for the Mac doesn't mean that an
individual user could not be targeted in a sophisticated phishing attack.
Again, even if the risk is very small, some people will want to err on the side of caution.

There aren't many free anti-virus programs for the Mac, but you could
always try ClamXav, which uses an open source antivirus engine.
It's a graphical front end to Clam AV, and also available from Apple.

Update: When I checked my Twitter account this evening, I found
that Graham Cluley from Sophos, a British antivirus company, had tweeted
about some videos "of Mac OS X malware spreading in the wild for @jackschofield
and any other skeptics!" I've added one above. It shows a social engineering
approach where users may install Mac OS X malware deliberately because they
think it's a codec, an HDTV player or other bit of useful software.
It's not a self-replicating virus, but then again, it is exactly
the same as a lot of Windows attacks.