My wife has a degree in early childhood development. Up until we had our first child, her plan was no spanking. Her parents didn't do it, so we shouldn't either. What she didn't realize was the willful, stubborn nature our daughter would inherit from me...
We spank. Not for every little infraction, but when it's obvious Abby is not listening and has no plan on listening, or is doing something that may harm her, we give her a swat on her behind to help her focus. She's two years old, I don't expect her to understand reason and logic. We also use timeouts or verbal discipline depending on the "crime". We're also not afraid to let her have her temper tantrum as long as we're not somewhere she can bother others. We're more than willing to cut an outing short to carry a kicking and screaming child back to the car. No means no.
We also use a lot of positive reinforcement. So, while we have a child who is exciteable and can be a handful at times, we also have one who knows how to pick up her toys when asked, is polite to a fault (she apologized to Mike several times, knows "please" and "thank you", and says "excuse me, sorry" when she bumps into someone at the store), and shares with everyone.
Chris