I like to pretend to call the police... let the driver see you write down a plate number and/or get out a phone and dial 3 digits. Look around for a street sign/house numbers as you make your 'report'. Even if they just catch a glimpse of you on the phone (or bike light, or rolled-up spare tube) in their rearview as they speed off, they're going to be worrying for the rest of the day, and will hopefully think twice before raging in the future, because maybe there's a report on them now.

Anything more than horn-honking, swearing, and engine revving, and I would call police for real. An aggressive close pass might be enough for me to call, depending on how close and how aggressive it felt. Fortunately, I've never been seriously threatened. I don't like the idea calling police either, but it feels like it's a service I can do that might help some other cyclist in the future.

Anger just escalates the situation, and then you're both in the wrong. Plus, you're out-gunned (maybe literally, but at the very least, he's in a car, and you're on a bike).