For a good, usable version for kids of the 10 commandments, see here.
A simple kid's talk: Who has heard of the 10 commandments? Can you name any of them? [Then put them on the screen and go through them.] The point of the commandments is to tell us who we are.
For example, We tell the truth. When we tell the truth people can trust us, and we want to be a church that people can trust. When we tell lies, people can't trust us because they don't know whether we are lying or telling the truth. Imagine if we lied all the time. What would it be like? No good, because you could never trust anyone. That's not who we are: we tell the truth, and we tell the truth to be trustworthy.
God gives us commandments for us to obey so that we can be the kind of people God wants.
