What is the woman holding in Hopper's painting, "Nighthawks"?

You can't tell here, but I believe it's a book of matches:

http://www.mystudios.com/art/modern/hopper/hopper-nighthawks.html

Looks more to me like she's doing that peculiarly female thing of examining her manicure.

http://www.artchive.com/artchive/H/hopper/nighthwk.jpg.html

Oh, my God, robboy, Sister WENDY?

I haven't examined the painting with a magnifying glass (although I suppose I could; I see it often enough), but I recall a discussion in connection with the Whitney exhibition about ten years ago. The curatorial verdict was "a book of matches."

I had no idea that you were a Sister Wendy fan, robboy. How utterly adorable.

You know, I coulda sworn she was double checking she had removed her wedding ring.

I'm actually a Mariner and Braves fan, frankie. The painting just happens to be one of my favorites in the world, having discovered Ed Hopper while I was living in NY. This one, and a few others like 'New York Movie', 'Early Sunday Morning', and especially 'Eleven a.m.' are in frames I made years ago. I wouldn't know Sister Wendy from Mother Teresa; just picked that site because of its close-up features. Anyway, my wife at the time was positive the woman in question is bored out of her gourd, and she's wondering how early she would call her boyfriend.

She's looking at her right hand, Peas. *

And so she is, robboy.

Spend much time in Chicago?

Yes, robboy dear, once I squinted close enough and eventually stumbled through my over-loaded handbag full of junk I found my glasses. I too, thought she looked bored out her brain. *

Nope, no Chicago for me. Do they wear wedding bands on their right hands?

Although on the other hand a diuretic coffee matches.

Just thought you might have made the occasional effort to visit one your favorite paintings in the world, robboy. It's always best to see them "in the flesh," if you can.

It's a very sad painting - they all look unhappy.

Notice too that while it is set in New York City at the top of the cafe it advertizes Phillies. That might mean something.