Since there's very little chance that a Mac will be infected with anything, there's just not enough demand for anyone to set up an online scanning website for Mac users. I've used Macs since 1984 and have never lost one minute of time worrying about, scanning for, or having to repair or restore a system because of a Mac virus, trojan or worm.
With that said, here are a few links for you.
Mac Security Suggestions
http://forums.macrumors.com/showpost...3&postcount=52
Protect yourself from imaginary Mac viruses for FREE with ClamXav
http://macenstein.com/default/2010/0...-with-clamxav/
ClamXav - The Free Anti-Virus Solution for Mac OS X
http://www.clamxav.com/
HTH