''There's nothing like some Will Forte sweat on your face!'' laughs the 26-year-old singer, who is lying under the comedian on a couch at Saturday Night Live's New York studio this December afternoon. With Maya Rudolph, the pair have been blocking out a sketch called ''Old Friends,'' which concludes with Timberlake and Forte shot by a sniper. Hence their prone position on the couch, and the sketch-comedian perspiration dripping onto pop-superstar face.

''People would pay a lot of money for that sweat,'' Forte faux-boasts to Timberlake.

''You should sell it on eBay,'' Rudolph concurs.

She's joking. Clearly, the only sweat worth its Internet-auction salt around here belongs to Justin Timberlake, this week's SNL host and musical guest. For this is Timberlake's time. He seems omnipresent in the culture, his celebrity status comfortably eclipsing even the megastardom he enjoyed at the height of 'N Sync's success. He's at Sundance with a new movie. He imitates Prince at the Golden Globes. And then, of course, he's the story du jour for the tabloid press and entertainment news shows, which have drooled endlessly over Timberlake's split with longtime girlfriend Cameron Diaz and his subsequent rumored ''links'' to a tranche of comely female celebrities including Scarlett Johansson and Jessica Biel.

But all this — the breakup, the alleged flirting, the awards ceremony high jinks — is merely the sideshow to his emergence as a genuine pop culture talent, the one real deal to survive the boy-band craze. On his second solo CD, last year's FutureSex/LoveSounds, Timberlake went for a whole new sound, a sonic departure from both 'N Sync and his first solo album, Justified. The result was massive success: two No. 1 singles so far; the introduction of the phrase ''bringing sexy back'' to the idiom; four Grammy nominations, including a coveted Album of the Year nod; and the fifth-best-selling album of 2006, shifting 2.4 million copies. While releases by OutKast, Pink, and Diddy underperformed sales-wise, Timberlake proved himself a rare beast — an established artist whose new release matched the commercial hopes of a music business in dire need of superstars.

''He is hugely important to the industry,'' says Barry Weiss, president and CEO of Jive Records, who has known Timberlake for nearly a decade. ''In the past three to five years it's become more and more difficult for American artists to sell overseas. He's one of the few that successfully sells in every country around the world.''

As if all that weren't enough, 2007 will also see the proper debut of ''Justin Timberlake, Actor,'' with at least three films boasting his thespian talents: Black Snake Moan (which opens Feb. 23), Shrek the Third (out May 18), and the Nick Cassavetes-directed Alpha Dog. The latter was released on Jan. 12 and garnered Timberlake a slew of positive reviews.

''He was born to do SNL,'' Samberg says. ''He's got charm and acting ability, but he also has comic timing. And then, when you start throwing singing into the mix, it's like, Oh man, you can make the dumbest joke sound great! And he has no problem looking like an ass. None whatsoever.''

''I liked him a lot,'' Samberg concludes. ''He's a silly man.''

The preteen Justin Timberlake, whose parents split when he was just a toddler, was anything but silly. ''I was a tortured young dude — to the point of rage,'' he says between mouthfuls of chicken paillard at Manhattan eatery Pastis. ''I literally walked around like this...'' Timberlake stares down at his plate, the star's face scrunching up into a dark glower before reconfiguring back to its usual friendly, open demeanor. ''My mom makes jokes. She goes, 'It's no shock to me you're obsessed with sneakers because that's the only thing you looked at for the first 10 years of your life.' And if I couldn't do something really well when I was a kid, I wouldn't do it at all. I wanted everything to be perfect.''

That drive carried over to the emergence of 'N Sync. ''I had so much power,'' Timberlake remembers. ''We were playing stadiums, and I could say, 'Hey, we should fly down!' And suddenly people are building rigs for us to fly down on. We had a blast doing it, [but] I was really a perfectionist.''

But by the time he went solo to record Justified, the committed perfectionist seemed like he couldn't quite hold it together. In fact, he had become a bit of a stoner. Timberlake has previously admitted that Justified was constructed in something of a marijuana haze. That partly explains, Timberlake says, his somewhat bewildered 2003 appearance on Ashton Kutcher's MTV prank show, Punk'd. Timberlake, who was tricked into believing that his possessions were being taken away by the tax authorities, seemed totally devastated — for a minute there, he was known as The Man Ashton Kutcher Almost Made Cry.

''I'll give you a little hint on that Punk'd thing,'' Timberlake says. ''That was back in my first-album creative days. That's why I looked the way I did, if that makes any sense to you.''

Can I confirm what you're saying here?

''I don't give a s---.''

Were you stoned?

''I was like, Yes, now I get to be like an Al Green!'' says the singer of his solo debut. ''Then the reviews came out: 'Pop album,' 'Pop album,' 'Pop album.' I couldn't f---ing believe it.... But it's just the nature of the world. At some point you have to realize you can't keep beating people over the head: I sing R&B, I sing R&B! Then you just become weird.''

The critical reaction sparked an epiphany. Timberlake realized there were things he could control and things he couldn't. ''And the ones that you can't control, you have to say, F--- it,'' he explains. ''And enjoy it!... So I was like, F--- it! If I'm a pop artist, then I don't just have to do R&B. That's why this [new] album sounds the way it does.''

Mostly co-produced by Timberlake with Timbaland, FutureSex/LoveSounds is short on traditional vocal hooks and long on thundering electronica-styled beats. Songs such as the title track and ''SexyBack'' barely sound like Justin Timberlake songs at all. The latter was such a departure, in fact, that Jive boss Barry Weiss more or less admits he had doubts when Timberlake suggested that it be released as the album's lead single. ''It was an unusual record,'' defends the label chief. ''It didn't sound like Justin vocally. It didn't have his distinctive falsetto-style vocals. It was a bit of a risk for all of us. But it was a risk that clearly paid off.''

Paid off? In spades. On top of the 2 million-plus copies FutureSex/LoveSounds has sold in the U.S., it has shifted an almost equal number abroad. The CD also ended up on a lot of best-of- 2006 lists, including EW's. But with Timberlake front and center in the public eye, a certain inevitable carping followed: Some critics wondered just who this young punk thought he was to be ''bringing sexy back.''

''Well, who the f--- is anyone?'' Timberlake asks. ''The thing I love about it is, at this point, people don't project it onto me. People don't come up to me and say, 'Hey, man, you're bringing sexy back.' They go, I'm bringing sexy back. But, yeah, obviously that's being pushed by the media — no offense. 'F---ing pretentious kid makes a statement.' They still love to call me a kid.''

''Like I said, I just choose not to participate,'' he sighs. ''That's what gets me by.''

When was the last time the coverage caused him to lose his temper? The singer pauses: ''It depends what you classify as losing your temper.'' Then, after a long silence, he offers this story: ''I was at the Grammy nominations and somebody asked me a question. It was like, Do you have any advice, you know, for someone in particular. [Though Timberlake doesn't specify, the ''someone'' is most likely his former girlfriend Britney Spears.] I looked at the interviewer and I said, 'I don't think so.' I walked off, and I was like, 'F---!' My manager [said], 'Let it roll off your shoulders.' And I was like, 'You're right.' But what is the point of all that? What does that have to do with anything?''

There is little doubt that Timberlake's biggest box office film of 2007 will be Shrek the Third, in which he voices Artie, a.k.a. the young King Arthur. And the singer wants to make clear that he secured the role without the help of the Princess Fiona-voicing Cameron Diaz. Rather, he says he was cast by Jeffrey Katzenberg after the DreamWorks cofounder saw him host SNL for the first time in October 2003.

''He said he saw me on SNL and was like, 'That guy is funny,''' recalls Timberlake. '''He has to play Artie.' I didn't bring it up with Cameron for a while. It felt weird. Like, 'Hey, guess what?...'''

But the big-budget Shrek the Third is something of a blip in Timberlake's nascent filmography. While he did perform in a straight-to-video thriller (2006's Edison Force, with Morgan Freeman and Kevin Spacey), Timberlake really wants to cut his acting teeth on indie projects. Alpha Dog tracks the ultimately homicidal activities of some privileged L.A. gangsta-wannabe kids. Debuting at the Sundance Film Festival, Black Snake Moan features the singer as a military recruit whose nymphomaniac girlfriend, a scantily clad Christina Ricci, is chained to a radiator by Samuel L. Jackson's Southern farmer after we see her developing uncontrollable sexual urges following Timberlake's departure. And he has also shot a part in Southland Tales, a new project from Richard Kelly, the director of cult hit Donnie Darko. None of these movies is destined to dominate the multiplexes of the heartland.

''That's comfortable for me,'' he says. ''There's enough pressure on me to succeed at the music box office. I'd just rather get better at this. It's a work of love. I'm really into it and I want to do so much more.''

Of course, Hollywood's dustbin of history overflows with music stars who tried, and failed, to make it in Tinseltown. Moreover, the singer's features are handsome enough to preclude him from many character roles, and perhaps too soft to scream ''movie idol.'' But similar things were once said of Will Smith, and Black Snake Moan director Craig Brewer has no problem comparing the two.

''Little by little, [Will Smith] made choices that edged him closer to being a better artist,'' says Brewer. ''And Justin is on that road. He could probably go the Glitter route. [But] that's not what he's chosen to do.... He's choosing roles that push him outside the comfort zone. That is a sign of someone who is going to have a career that is going to last decades.'' Samuel L. Jackson is equally effusive in his praise: ''He went for it every time,'' says the veteran actor of his costar. ''In fact, there was one point where I said, 'Wow, he's gonna run out of tears in a minute.'''

''Hey, have we paid the check?'' asks a clearly concerned Timberlake after our post-meal coffees have been cleared away. Dinner with the star is nearly over, which is a shame. He is remarkably good company: bright, funny, informed, and voluble on almost any subject that does not clash with this Southern gent's aversion to kissing-and-telling. His reticence even applies when the kissing happens to be on screen. Asked what it was like to film Black Snake Moan's opening raunchy sex scene with Ricci, he protests that he's ''not gonna answer those questions.... Christina is hot, by the way. But, you know...''

He is also, obviously, someone who believes in doing the right thing. And right now, that means disappearing to hunt down our waitress and ensure that the check has been taken care of, despite the 99.9 percent chance that his publicist would have already done so.

When Timberlake reappears, he has a big smile on his face. ''You missed something there, dude,'' he says. ''I was at the bar and this girl said to me, 'Hey, I'm bringing sexy back.' And you missed it! You're a terrible journalist.''

''I'm joking,'' Timberlake laughs. ''I'm just breaking your balls...''