Originally Posted by Isaac Mickle
In the US, it also varies by region. In some areas the Ph.D. is admired on the card. In other places it is considered naive and uppity and embarrassing.
This is true and it also depends on the University. At technical schools (RPI, MIT) it is more common for a Professor to go by the title Doctor, while at liberal arts schools it is more common to use the title Professor---at least in my experience.
As for whether it is used at labs like JPL, etc, I find that it is rather common to have Ph.D. on one's card. This seems to be the norm at DoD labs. On the other hand, if I recall correctly, it isn't common at, e.g., LANL.
In any case, I follow the lead of my colleagues and put Ph.D. after my name (with the periods, which I also think looks better).