How long can he hang on?

David Blaine proclaimed, “I’m doin’ all right,” after starting his latest endurance challenge Monday: 60 hours hanging upside-down, without a net, above Wollman Rink in Manhattan’s Central Park.

Blaine – sounding nasal from sinus pressure – kept smiling while describing the “enormous push of blood” that made it feel like his head was “about to explode.”

“The legs go pin and needle very fast,” the magician said. Stretches – kind of an upside-down sit-up – seem to help.

Blaine, 35, is scheduled to exit from his perch at the climax of a live, two-hour ABC special, “David Blaine: Dive of Death,” on Wednesday.

The biggest danger he faces is going blind, at least temporarily, from the increased blood pressure in his head, says Dr. Massimo Napolitano, who is advising Blaine on the stunt.

There’s also a risk of swelling and cramps in internal organs, he said, adding that it could yield valuable data for doctors.

It’s the latest in a series of stunts by Blaine, who as a child was intrigued when Harry Houdini dangled from a crane by his ankles while escaping a straitjacket.

A run of rappers

Eighties rappers Run-D.M.C., known for their duet with Aerosmith on “Walk This Way,” are among the new nominees announced Monday for the Rock and Roll Hall of Fame.

The others are Metallica, The Stooges, guitarist Jeff Beck, singer Wanda Jackson, Little Anthony and the Imperials, War, Bobby Womack, and disco/ R&B group Chic.

Grandmaster Flash and the Furious Five opened the door for rap at the Rock Hall last year as the first hip-hop act to be inducted.

Walk this “Runway”

Lindsay Lohan will appear as a guest judge on the reality fashion competition show “Project Runway” when it debuts its new season next year on its new network, Lifetime.

Meanwhile, TV viewers can catch her reprising her guest role as Betty’s former school bully Kimberly on ABC’s “Ugly Betty,” which premieres its third season on Thursday.

On the outside

Pat O’Brien, already infamous for obscene voice mails before entering rehab in 2005, has been fired from “The Insider” over interoffice e-mails trashing Lara Spencer, who replaced him as host in June.

In describing a trip to Iowa, O’Brien said that middle-class folks “want to vomit” watching Spencer picking out accessories.

Hey, l-a-a-dy – not gui-l-l-ty

A Las Vegas judge has dismissed a firearms charge against Jerry Lewis.

The 82-year-old entertainer was cited in July for attempting to carry an unloaded concealed weapon through McCarran International Airport.

Lewis said the weapon was a gift that he’d placed in a carry-on bag more than a year ago and forgot about.

The birthday bunch

Actor Mickey Rooney is 88. Singer Julio Iglesias is 65. Actor Paul Petersen (“The Donna Reed Show”) is 63. Singer Bruce Springsteen is 59. Actor Jason Alexander is 49. Actor Chi McBride is 47. Actress Elizabeth Pena is 47. Singer Ani DiFranco is 38. Rapper-producer Jermaine Dupri is 36.