Not to be the one voice of dissent, but I would spank in extreme cases. The 10 year old that pulled a handgun on a woman making an innocent joke to one of his friends on Halloween who was released without charges would be spanked when I was calm and would be lucky to get privileges back by Halloween 2012. Had it been my 12 year old that pushed a shopping cart off a fourth story parking garage at target for fun and left a mother clinging to life and laughed about it at booking he would count himself lucky that he was in police custody. I don't think smacking a child's hand for minor offenses does any good, but endangering the lives of others would qualify a spanking in my mind.
The thing is...I bet that kid WAS spanked. Studies show children who are hit, are more aggresive. Research it!
I've taken child development classes and seen both sides of the argument and I get what you're saying. If someone does something you don't like it's alright to hit them if they're smaller can be a message that's sent if the spanking doesn't match the crime, but if my child is displaying sociopathic behavior a consequence that they fear would be what I would want them to associate with their behavior.