[StoryOfGrace]

As others have said, self evaluation of what you learned from spanking may be eye opening for you. I know it was for me.
When I joined GCM a year ago (awe it's been a year ladies! ) I would have easily said this:

When people would talk to me about spanking I would easily and honestly say: "I needed it." I knew I was the kind of kid who who only refrain from doing X if I knew I was going to get a spank.

Several times in the past (pre-kid, oddly enough ) I've argued for spanking saying how I was the "type of kid who needed it." After self-reflection and evaluation of what spankings taught me, I know now that it's not true.

Spanking and punishment taught me to:
-Lie. "I'm sorry I made you mad Mom. I'm sorry I did X." Really, I wasn't sorry. I just didn't want to be in trouble any more. I distinctly remember several times where I apologized and didn't mean it, just so I could get out of the punishment.
-My feelings didn't matter. I was just "the kid" and had no right or reason to be heard or understood.
-I deserved to be hurt. What a horrible dynamic to teach a child...really, think about it.

I could go on, but those are the big ones.
Another thing I consider:
My DS goes to play school a couple of days a week. They have a very positive discipline approach to dealing with all the children in their class. I figure, if they can get X number of kids to behave so well without punishment or spanking, then I can do the same with one.