Help! Metal stem in tread?

Edit 3: It was just stuck in there tight, not puncturing the tire. Thanks!

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Sorry for the whiny "Help!" subject, but I'm leaving for Burning Man tomorrow morning. I was hoping to leave at about 6AM, but I may have to wait until the tire shop opens at 7:30 if I don't get an answer quick.

I was loading groceries into the car just now, and noticed a metal piece embedded in the tread of my right front tire. I took a few pics with my camera phone:

Edit: The forum seems to think these are videos, they're not. Please click on the title link for each picture, and a description of everything is below. Thanks!

Edit 2: Replaced cameraphone pics with better quality ones.

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The bit on the right is a tiny pebble that was easily flicked off, but I'm worried about the part on the left. It's metal, cylindrical, almost but not quite to the top of the tread. It appears to be in two parts, with it a little narrower in the middle. There is a tiny hole dead center on the top. I picked at it lightly, and it's firmly in there. I didn't try harder just in case it is a foreign object piercing the tire.

Now, it almost looks like it should be there... Tread indicator? It's right after "Goodyear", and almost immediately to the right of the tire's seam. I looked on the other tires, but couldn't find anything else like that. These are OEM Integras on an 09 Prius.

Ignorance was bliss...