I hope this does not start a Virus war, but these are the features I looked for when selecting a virus program:
• Scans for both PC and Mac viri and Trojan Horses (I am very apprehensive about even forwarding a PC virus to PC colleagues).
• Can scan stuffed files & folders without expanding them.
• Runs automatically and unobtrusively in the background.
• Can automatically scan downloads & removable media upon insertion.
• Free monthly updates (electronic updating nice, but not required).
• Works with both OS 9 and OS X.
While I have great distain for Norton's utility programs, it is my experience their Anti-Virus program (v9.0) meets all the above criteria.
Of course, to each - his own...
Harv