Hi All,
Having a few problems with the search feature here, so I was wondering:
What Antivirus do you use?
You do not need an anti-virus for OS X. There are not now, nor have there ever been, any viruses in the wild that effect OS X.
OS X is not immune to viruses, but thus far there have been none in the wild that have been a problem or infected Macs. There are other forms of malware that can effect Macs, but the best way to avoid them is safe computing.
If you really want to, you can get ClamX, which will scan for nasties and quarantine them. I use it once a month and it cleans out a bunch of harmless (probably Windows) junk which has no impact anyway. The nice thing about ClamX is it doesn't run in the background, and so it doesn't use any resources until you open it for a scan.
Mac Virus/Malware FAQ
http://guides.macrumors.com/Mac_Virus/Malware_FAQ