I don't watch either of these shows but apparently they wear them on Mad Men
and Boardwalk Empire
and Matt Bomer......
Okay he's not wearing one but he came up in google image search for "collar bar" and well...
it's MATT BOMER.
But I think I rather like these collar bars/pins, gives a certain sophistication and elegance to the mans' wardrobe. I like how if elevates the tie knot, quite dapper indeed.