Taking a Spin on Hydrogen

This is why everyone wants to be an ambassador. Germany's man in D.C., Klaus Scharioth, has spent the past few days tooling around town in the new hydrogen-powered BMW -- just one of the cool perks of a cool job, though he'll have to give it back to the company. (Kind of like how Brad Pitt got to borrow one for the "Ocean's 13" premiere.)

We caught up with Scharioth at the embassy's massive Day of German Unity party Wednesday night (2,000 guests, a delicious Erzgebirgischer Buttermilchgetzen like mom used to make, some nice Riesling to sip through the speeches). Of course we wanted to know all about his sweet new ride. "It is good," he said, adding that "we have to explore all kinds of energy sources." So true, but more important: How many seconds from 0 to 90?

"I didn't have my stopwatch," he said, diplomatically. Scharioth also insisted he's been too busy with work to take it out on the highway.

A couple of the "Hydrogen 7" cars were on display at the party, along with free bottles of water labeled "exhaust," because water vapor is supposedly all they emit. You have a sip first and tell us what it's like.

Alums, Celebs Coming Home to Howard

Howard University President Pat Swygert is expected to announce today a typically glitzy lineup of celebrity guests to officiate at this month's Homecoming -- his last before he retires. At the top of the roster as "grand marshals": hip-hop teen idols Bow Wow and Omarion . (Crazy coincidence: They've got a collaborative album they'll be promoting this fall.) R&B legend Chaka Khan (who also has a new CD!) will serve as grand mistress of ceremonies for the homecoming parade; other participants will include actress/alumna Taraji P. Henson, supermodels Tyson Beckford and Melyssa Ford, and Stephen Nichols, an '07 grad whose claim to fame is a stint on MTV's "The Real World." Does that count? We'll let his classmates decide.

HEY, ISN'T THAT . . . ?

Bono hanging out on the second-floor lounge of the Sonoma wine bar and mingling with regular patrons Tuesday night well after the private reception he was hosting there for Hill types wrapped up. The Irish rock star and African poverty activist (black pinstripes, black shades) signed autographs, posed for pictures, sipped a good Italian red.

Cheech Marin closing down the Palm Wednesday night with a party of 10. The veteran comic and character actor (Hurley's dad on "Lost"), in town for Congressional Hispanic Caucus festivities, walked out wearily at midnight holding hands with a woman in red.

LOVE, ETC.

Expecting: Yankees star Alex Rodriguez and his wife, Cynthia. The couple endured an N.Y.C. tabloid frenzy last spring when paparazzi caught the likely American League MVP out on the town with another woman, but they seem to have moved past that. Their second child is due in the spring.

Split: Actor-rapper Nick Cannon, 26, and fiancee Selita Ebanks, 24, the Victoria's Secret model he proposed to via the Times Square Jumbotron last spring after three months of dating. Huh -- really thought that one would last. People mag assures us they remain best friends.

THIS JUST IN . . .

The Ballou High School band's Lewis Franklin, left, Kenny Horne and director Darrell Watson on "The Ellen DeGeneres Show."(Mike Rozman - Warner Bros.)

Ballou High School marching-band director Darrell Watson grooved through a couple of dance steps with Ellen DeGeneres, and his kids performed "I Love the Way You Move" on her talk show yesterday. In return, the host -- wowed by a new documentary on the nationally ranked band from the crime-scarred neighborhood -- presented the band with a check for $25K, the school a check for $75K and heaps of school supplies for students.