http://www.clamwin.com/

They seem to be in their infancy and not a very good product right now. They are asking for help and if you want to try it and or help them develop it..... follow the link above.

I personally think from the looks of it AVG is tons better right now.

Quote from their website
Please note that ClamWin Free Antivirus does not include an on-access real-time scanner, that is, you need to manually scan a file in order to detect a virus.