I have never heard it as Eileen but Eily (SP?)

Also, regardless of what the Irish Irish like, Irish Americans, and I am one, love their shamrocks. I call it the curse of the Irish. If you have a bakery, an auto parts store, a tavern, and have an Irish name, you most likely want a shamrock on the sign. I have the curse myself and see it as a great honor to have such a wonderful symbol. Irish can be quite condescending to Irish Americans and quite insulting, especially around St. Patrick's Day, which is basically an Irish American and not Irish Irish holiday..when all the plastic paddy insults come out.

You should not insult people's ancestors, and that is what a lot of this comes down to. I also think that the shamrock is sort of like a passover symbol where you hope that some token will spare you some of the troubles that our ancestors faced.