Nice to see that OnCare
has made it out into the wild. I was on the beta for OneCare and found it to be very usable. I've used Norton AV and McAfee virus scanners in the past. I really have not liked the 3rd party antivirus apps because they eat up alot of resources and cause compatibility issues. OneCare seemed to play nice and I didnt notice any system degradation while using it. If your still riding bare back I highly suggest you try out OneCare.
P.S. another really nice light weight virus scanner is portable clamwin
. It's free and can run from your usb thumb drive. Good for those times when you have to play IT guy for your family or friends. :)