Covert Channel: ASCII Art Over ICMP
An anonymous reader writes "Have you ever had a particularly lossy Cisco ping, which you were sure was trying to tell you something? I mean, really *tell* you something. Echoart allows you to return a simple ascii art image in response to a Cisco-style ping."
http://www.unixauthority.com/~fiskeja/mirror/mirro r1.internap.com/echoart/