May I ask why? The number or Linux virii out there is rather low and for the most part you have to give them root access to do any damage. I've ran linux for many years now and the only time I ever run an AV solution is to protect mailboxes. For this solution you use something like clamav and have sendmail use it to scan the outgoing mail.
Panda also makes Linux antivirus software. I agree with chickens that there really isn't much of a need for it; however, it does make people feel safer to have AV software I guess.