It really matters on what's been done. Time-outs and loss-of-privlidge are what I plan on using once my son is old enough to understand (can't very well discipline an 8 month old, not that there's any reason to in the first place).

Haha, my parents never hit me, except for my mom. I was maybe 12 years old, and she had me mad something fierce, and I called her an asshole... she smacked me so hard that when I tryed to run away I ran straight into a wall, which irronically hurt a hell of a lot more than the slap.

I learned real quick to not disrespect my parents, and was never hit again.