I often receive automated messages from my friend which say "lol, I just got ipod from www.domain.com" or "check my newest picture at www.blabla.com" Obviously their computer is infected by virus or some sort which automatically send message to their friend. How can we do this also? What tools we need to do this? I am interested to do this because we can easily get traffic to our site and monetize it. Sorry if this is a noobish or lame question, just say so .