I voted "have children and spank" even though I really have only spanked once. I believe that spanking, and corporal punishment, is reasonable.
my son is 8. when he was 3, he had a major tantrum in a mall at christmas time. I picked him up to carry him out, and he wacked me, hard. I tried to get him to calm down, and he basically was yelling and fighting. so I pinned him down on the floor, and said, very calmly "I am bigger and stronger than you, and if you try to use violence then you will always find somebody bigger and stronger than you, so it isn't a good idea". he kept fighting, so I poked him with my index finger on his forhead. I said "see, I can hurt you with just one finger, do you really want to keep fighting?" he said yes, so I poked him again, and then he gave in and I made him appologize. about 3 months later he started to have a tantrum, and I showed him my index finger, and he calmed down. that was the only violence I have had to use on my son. his normal punishment (again, not very common) is that I make him bring me a toy and I either break it or put it away for a period of time.
one of my 3 year old girls had a tantrum a while back, and after trying to calm her down several times, I put her over my knee and slapped the top of her theigh a few times. that worked. I haven't had to do it again.
my kids are very disciplined - I get compliments all the time from other parents on how polite and well behaved my kids are, and how disciplined. they stand up to speak to adults, for instance, and they say "please" "thank you" and "excuse me".