macdevcenter on ClamXav:

"This very helpful article goes through the steps of installing the software, setting up the preferences (by default it only scans when you tell it to, for all you antivirus haters out there) and includes an interview with the developer that wrapped GUI goodness around the command line tool CalmAV (which, by the way Apple ships with OS X server)."

(Via The Unofficial Apple Weblog (TUAW).)