slowing down or stopping - yes
* Tuning right or left - yes
* Changing lanes - yes
I signal for just about everything, in fact. Whenever there is a car within view, I attempt to make some sort of gesture. This includes when they approach from behind, too.
I also wave "thanks" when they are considerate and I wave when they pass and I wave - alot. I'm nice like that.
Yes, I said it... I wave at cars.
We share the roads, cars and cyclists. This may seem a naive approach to some cyclists, many of whom feel the need to be hatin' on cagers.
Me, I see it as non-adversarial, more of a partnership - even if the car drivers are not aware of it just yet.
I also wear red gloves, bright shirts and a fluorescent "doo-rag" to enhance visibility. On top of all this, my big Clydesdale @ss makes me pretty hard to miss.