Sometimes a raised eyebrow can speak volumes. A little light mockery can also do wonders.
I had that problem earlier this week. It was just me and a guy on facebook arguing that marriage is not a right and it dissolved into him trying to prove that god existed to me while I was just trying to prove that evolution could happen to him--he answered every bit of proof with completely unrelated blocks of questions, and I eventually gave up and had to block him.
Perhaps in front of someone, it is worth it, but online...no, don't even try.
I am tempted more and more to just shout "STRIKE ME DOWN NOW GOD, IF YOU ARE REAL!" or similar and see what happens. I know nothing will but the looks on their faces could be as priceless as a mastercard commercial.
Imagine you're on a train car and you're sitting at a table with a Young Earth Creationist having tea and debating religion. On the table is also a brief case with science that is proven and also compromises the Creationists arguments. They stand up while still talking to you and holding your gaze, while simultaneously throwing proven science out the window and only the look in their eyes tells you what they're thinking... "Look how easily I deny what is irrefutably proven with rock-solid evidence to defend my lies from the barrage of education you're about to use to "school" me, while simultaneously pissing you off because it makes me feel better and helps me make up for the fact that I know I'm wrong."
That is why you can't argue with a YEC. lol. Am I wrong?