I was going to write Miss Manners about this one but I figured I would generate some more interesting responses from here.  If you see a provider who gives you what you consider a GFE, is it appropriate to call that provider just to say "hello, how are you?"  Just curious.

I think an e-mail would be more appropriate and leave it to her to either call you or respond by e-mail. If you write her and state just want to say hello when ever you have a minute give me a call so we can talk. It gives her the opportunity to call you at her earliest opportunity and call when she has the time to chat.
I really like e-mail because I can respond from home while the kids are doing homework and nobody needs to hear the conversation or also respond in the middle of the night and nobody gets woken up. It is just easy, fast and convinient.

Kisses & Licks........
Mara of San diego

As usual, Mara hits the nail directly on the head. Email is best. If one was to call a provider several times when it is inconvenient for her, she may consider that person a "pest". With the emails, one may avoid this label.

I agree with Mara e mail is best.

My ATF prefers phone contact so, like so many things, it may vary based on the individual.   It's easier for her to talk in the evening between appointments as she doesn't have her computer present.