I would have to echo Wynette & Cottagegarden. Personally, I haven't been able to spend a lot of time with my birds so they aren't overly friendly. I wouldn't say they are overly flighty either. They tolerate my existence and presence but don't come running over to jump up in my lap and be carried around.
Having said that, here is a quote I received recently from one of my customers, "The Ameraucana is the friendliest by far she is going to be a real joy!" and another wrote, "The new favorite around here is the ameraucana, we should have gotten 1 more."
Both of these ladies talked about how friendly their Ameraucanas were. One said the little pullet would fly up on her shoulder and even flew up on her husband's back one time when he bent over to do something. They don't have a large flock and spend quite a bit of time with their birds though.
God Bless,