Ksplice » Hijacking HTTP traffic on your home subnet using ARP and iptables - System administration and software blog
http://blog.ksplice.com/2010/09/hijacking-http-traffic-on-your-home-subnet-using-arp-and-iptables
"Let’s talk about how to hijack HTTP traffic on your home subnet using ARP and iptables. It’s an easy and fun way to harass your friends, family, or flatmates while exploring the networking protocols."