Virustotal released a Mac OSX version of their Uploader for their well known virus scan service.
No virusscanner at hand and your computer catched a nasty virus or malware?
Microsoft Malicius Software Removal Tool or short MSRT is a neat tool to scan for and remove malicious software including (Blaster, Sasser, Mydoom and many others).
A few years ago, Google aquired the leading security scanning page VirusTotal, which enables you to scan files against more than 53 well known virus scanners and malware scanners.
Until now, you had to navigate to their page and upload one file, wait till scanning finished and then upload a different one.