How Irish am I?

Happy St. Patrick's Day everyone, although I realize that as I write this the day is almost over. I heard an interesting ad on TV yesterday. I'm sure you've heard the commercials promising to analyze your DNA and tell you all about where your ancestors came from. Well yesterday the ad took a slightly different twist, promising to tell you just how Irish you are. As far as I know my father's family was all German as far back as forever. My mother, on the other hand, always said that while her ancestry was predominantly German there was a little bit of Scots Irish and a tiny bit of French Huguenot mixed in there somehow. So maybe, on St. Patrick's Day I can claim to be a tiny little bit Irish without spending the $99, or whatever the charge is, to have my ancestry revealed. I have a friend of English descent who can trace his family all the way back to British royalty.  Maybe I could trace mine back to St. Francis? Oh,wait - he wasn't Irish was he?