Suddenly, the explorer found himself face to face with an ... Oprah

Somewhere during taping of the seventh segment, it hit Dan Buettner: "I was on with Oprah!"

For the full hour (4 p.m. today on WCCO-TV), Oprah and Dr. Oz discuss the research that led to Buettner's best-seller, "The Blue Zones: Lessons for Living Longer from the People Who've Lived the Longest."

Said Buettner: "I had never even met this woman, of course. She's kind of a legend and all of a sudden she's there. I put my arm around her." He joked with her: "At one point I had her grinding corn [for tortillas]. She had this supple movement. I said, 'Oprah, if broadcasting ever fails you, another career awaits you.' She looked over and kind of snickered." (I didn't ask for specifics because I'm sure it wouldn't have survived the editing process.) "I think I was on for six or seven segments, then it hit me and then I started tripping up a little bit. You'll see me get tongue-tied."

As preparation for the show, Buettner, a world explorer, spent five days in Costa Rica with Dr. [Mehmet] Oz. "I got to trudge the mud with him, which was a blast, to take him to these off-the-grid cluster of villages, where these people reach 100.

"I went down there with Barbara Walters' people [for '20/20' segments] in December, and it was a completely different experience than Costa Rica with Oprah's producer. The producer carried on her wrist a little bag about the size of a brick, just full of $100 bills. Everywhere the producers went, they saw people in need, people who needed medicine. They'd say, Make sure this person gets what he needs," Buettner said.

Dr. Oz went to Costa Rica "as a reporter for Oprah, but he also went down as a doctor, so he had his bag," Buettner said. "When we were interviewing these 100-year-olds, Oz wasn't like, Let's get the story and get out of here. He was taking their blood pressure, listening to their hearts, assessing [needs]. In one case, there was this 100-year-old and it was pretty clear he was vitamin B12 deficient. Oz turned to this producer and said, We need to make sure this man gets these shots.

"It was such a vastly different mindset than most media organizations, which will go to a place and kind of expect everybody to jump to their needs. Oprah's people really go with a different intention: We're getting a story here, but let's give something back. I never experienced this."

Tiegs, who has already been on Oprah's show a couple of times, could not make the trip because she was busy shooting her reality special for ABC, Buettner said.

A P.S. on Symbolina Prince apparently did arrive home in Minnesota last week just as that stink bomb he dropped in the New Yorker started to smell.

The wifely half of a couple told me they were on the same U.S. Airways flight from Vegas to Minneapolis that Prince took. There was a flurry of last-minute seat-changing in first class before Prince ran onto the plane ahead of a "gorgeous, flawless woman" and guy who looked like 007's Oddjob, both of whom walked on the plane like normal people.

A new challenge Minnesota's Liz Halloran is leaving U.S. News & World Report, where she was a senior editor, to be a Washington correspondent for NPR's website.

Halloran sounded sluggish when reached Friday morning in D.C., probably because her U.S. News colleagues threw her a going-away party Thursday night. "NPR has such a great, trusted reputation that they want to get into the online news biz, too. So they hired me and I think they are going to be building it quite a bit over the next year or so," Halloran said.

"We have closed the reservations for our house," Halloran joked. "The Swann Street Bed & Breakfast is full, although we have floor space. If you are a close-enough friend or important enough, we will pull the rug for you. Two of my best friends from Minnesota and then my brother, his wife and three kids" have booked space at Halloran's home.

As someone who didn't think Barack Obama supporters were searched thoroughly enough for his Target Center appearance, I asked Halloran if she thinks it's a good Inaugural Day move for President Obama to get out of the armored presidential limo and walk a piece of Pennsylvania Avenue on the way to the White House. "It would be a great thing to see him and the new First Lady walking part of the route, but it's up to his security," Halloran said. "It's a tough one."

Not for me. I'm against it, unless there's a Barackmobile ready to roll.