My father was born in Sicily and I always thought that Di Giacomo (from/of James) was a Sicilian name. When I was growing up in New York, I never came across another Di Giacomo. But since I moved to the NJ-Penn area the name is more common. I don't believe we are all related: there are Di Giacomos all over Italy. I read somewhere that the first Di Giacomo settled in Arkansaus in the 1800s. Also, there is a Di Giacomo coat-of -arms -- how authenitic it is I don't know.