Okay...I'm sticking my toe in the water....

Quite the Michigander

I've heard that folks in Michigan do it with their hand!

It's a cultural phenomenon. I tried not to the first few years I was here, but really, it's quite handy. (sheesh) I wonder if Italians show people where they live in a similar way... (shutting up- living in Michigan also makes you more corny than you ever were, I'm from NJ so it took longer for me, but alas, 8 years in..)
Welcome to the forums!