Antivirus on a network attached storage device?

Factual Questions
1

Now that network attached storage devices have made their way to the hoi polloi (i.e., I have one), have any of the anti-virus companies expanded their capabilities to run checks on them? I have a Linksys NAS 200 running two drives in a mirrored RAID, and both my machine (XP) and my wife’s (OSX) store all sorts of documents, images, and sound files on it. I’d like to protect it, but so far so-called enterprise pricing has kept me out. Any good, free/cheap solutions out there? Zone Alarm, Linksys, AVG, and Symantec have either said no or not responded to my questions, and Googling has left me in the lurch.

Thanks,

Rhythm

2

Any reasonably featureful non-shareware AV package will be able to scan drives other than just your HD, whether they be memory cards, USB sticks or NAS devices.

What sort of extra functionality are you thinking of?