my 2 cents:

I have linux on my laptop, dual boot w/ xp but mostly use linux. I have no AV installed on in linux, don't need it. The system has a FAT32 partition used for files that I set to mount at boot in linux. There is absolutely no way that any virus can get onto that partition or onto the ntfs xp partition when I'm running linux.

I also have 2 deb server, no antivirus on those either. They are just www servers, no local mail delivery.

The only real need for av on a linux system is to thwart the spreading of windows viruses via samba shares or email systems. Heck, I have av on my windows systems but only use em when scabbing client's systems. I haven't run av auto-protection in 6 yrs.