a little help here, please...

So, what do all of you do when your toddler repeatedly uses the word "no"? I am not talking about when she yells it at us, we know what to do when she does that. But, I am speaking of the repeated "no, no, no, no" that she says when I put her on the changing table, when she's riding in the car, or at other seemingly random times. I can't really tell if she is saying to to us or just saying it. Sometimes it is at a normal decible and sometimes it is at the top of her lungs. Again, it's at these really random times.