I'm playing New Vegas on the 360. I noticed that the Hotkey menu (using the D-pad) has an aparantly permanent icon in the Up position. What is this? Can I get rid of it? I don't remember anything in the game mentioning it (though I am only to Primm, right now), and I couldn't find it in any FAQ, the official game guide, the manual, or here on the forums. I had a perfect layout of my hotkeys in Fallout 3, and this thing greatly impedes that layout.
Notes on the game I'm playing:
I've gotten to Primm, clearing out the Escaped Convicts.
I'm playing in hardcoe mode.

Preemptive thanks for the help!

That's for swapping ammo types in your equipped weapon (hollow point, armour piercing, etc.), and no, you can't get rid of it. You lose one weapon slot for this new feature. (Even on PC, although we have lots of other keys we could have used.)