Hmm. I punched someone on the chin in high school for stealing my book and generally being a bullying twat. Also someone else at school for throwing water into my tent, again on the chin. Both of them were a *lot* bigger than me, I think they were too shocked to react as I was a geeky girl with a very good disciplinary record!
I don't recall properly lamping anyone on purpose since then, or not off the top of my head. Been desperately tempted on many occasions though.