I work as a Campus Police Officer (Sergeant) at a small midwestern college. Basically though it's nice that you're trying to be proactive, in reality getting a cop's badge number won't do anything. Anybody and everybody who thinks he is being clever will ask me for my badge number. I will give him that and my last name. It's no secret. That's why I have both displayed.
Additionally, in regard to your statement that people should tell cops that they know their rights, that's not really going to help them. Unless you are a lawyer or judge or another cop from my jurisdiction, chances are extremely high that I know more about your rights then you do, as that is my job. Chances are also high that if you annoy me I will find something technically wrong with whatever crap it was you were trying to pull and your warning will become a citation.
As an aside, I wouldn't bother taking notes of dates and times you've encountered police. It will end up making you look as if you are constantly getting in trouble. If you really are being harassed, get video footage of the event. Otherwise mind your local ordinances, and I guarantee your encounters with police will become less frequent and more pleasant. Addressing the officer as officer also helps.