Ip spoofing is one of the easiest tricks in the book. At www.neworder.box.sk they have an entire section devoted to ip spoofing tools and techniques. Some tools like Command Spoofer and Dr. Spewfy are widely distributed on the internet and come with books such as Hack Attacks Revealed. And to find out more about ip spoofing read an ariticle called Ip spoofing A mammoth Discription.