The folks over at Datafellows list Navidad as well.
blue clicky thing to http://www.datafellows.com/v-descs/navidad.htm
This outfit provides a freebie virus-checker called f-prot for dos, and frequent virus definition updates.

If you get into the habit of running a virus-checker over any attachment before you open it - especially *.exe and *.doc files, you'll minimise your chances of picking up a virus.

PS: To Steve - in the absence of a blue clicky thing, you can always copy (click and drag) the web-address (URL) and paste (Shift + Insert) or (Ctrl + V) it into the address line of your browser...

Cheers