Oh, remembered another traffic one:
You don't have to wait for a green light to make a left turn from a ONE WAY street onto a ONE WAY street. As long as you come to a stop first, and there's no sign prohibiting such a turn, you can go for it.
I didn't realize that one until I looked it up a few years ago. And, again, it's possible some city somewhere doesn't allow you to do this, so check with your local authorities first.