CARRIE UNDERWOOD decided to "out-accessorize" everyone at last night's Grammys . . . by wearing a $31 million necklace. --For those of you who care about such things: It's an oval, pear, marquise and white diamond necklace . . . and it's 381 carats. It was designed by some big shot Beverly Hills jeweler named Johnathon Arndt. Carrie tried to sound humbled by it . . . but really, then why wear the damn thing? She told E!, quote, "It's heavy on my soul. I'm afraid someone is going to tackle me and steal it. It's worth more than me."

DIERKS BENTLEY'S favorite place to hang out during the Grammys is the hotel bar. He says, quote, "There's actually a bar in the hotel that we refer to as 'Bar Nashville'. It's not the cool spot to be seen. But it's easy access to the bartender, and it's where all the Nashville guys hang out."