Standup comic, actor, author, talk-show host, Jon Stewart could be dismissed as a show-biz jack-of-all-trades, master of none. "I like to be not good at anything," he explains with typical self-deprecating aplomb. "So I try to keep hopping around."

Yet the consistent element of Stewart's career, in all its various forms, is a high degree of humor, especially off-the-cuff wit. That's a quality he displays time and again during a recent conference call with TV critics trumpeting his debut as host of The Daily Show at 10 p.m. today on Comedy Central. "I've been to talk-show camp this summer," he says of his preparations for the new gig.

If there is one person who wouldn't seem to need any remedial training in that area, however, it's Stewart. A gifted standup comic, he first attracted public notice with a talk show on MTV. That led him to be pegged for a syndicated late-night show to replace Arsenio Hall when he got out of the hosting business. Although praised by critics, neither program attracted a mainstream audience, and when the late-night gig was canceled Stewart shifted into small, comical acting roles in feature films, such as the recent The Faculty, also doing some nice work during the last season of HBO's Larry Sanders Show.

Along the way, he kept his hand in the host trade by filling in for Tom Snyder occasionally on The Late Late Show on CBS. Stewart was widely considered the heir apparent to Snyder, but an odd thing happened on the way to the coronation. Stewart was passed over for that post by Craig Kilborn, who replaces Snyder in March. Now Stewart moves over to fill Kilborn's previous job as host of The Daily Show.

Many show-biz prima donnas might have rejected that course, but Stewart expresses nothing but excitement and anticipation at the move. "In the first two or three months," he says, "I'm just going to be trying to get up to speed with the well-oiled machine they already have going there." Although Stewart allows a little sarcasm to drip into his voice there, he is only half joking. With a crack writing staff under Kilborn's stewardship, The Daily Show has established itself as a biting news satire. "This show is a little different from what I was doing," Stewart says. "That show was probably a little more freeform. So this is going to be a question of getting used to bits."

The Daily Show is more formatted than the standard talk show. "That makes it easier, easier in the sense of knowing the parameters of the gig," Stewart adds. "What I like about it too is the fuel of the show is not just pure celebrities. You don't live or die on whether Brian Austin Green has a great story, which is sort of what you did on the other show. The fuel of it is really the daily fodder of the news, so it's more comfortable in that I'm confident the world will provide us with a great deal of chaos."

Does that mean Stewart is rooting for an extended impeachment trial in the Senate? "That puts me in an uncomfortable position. 'Are you hoping for the dissolution of our government?' Yes," he adds matter-of-factly, "and I hope O.J. presides over it. I'm in the uncomfortable position of cheering for chaos because that's where I can make the most muck. But, you know, if it's not that, I'm confident I can make it something else."

In fact, Stewart seems to relish the idea of stepping into a routine gig for a while. He recently published Naked Pictures of Famous People, a fiction collection of humorous stories. "I really enjoyed doing the book," he says, "but you don't get any reinforcement. You just sit in a room being yourself for a long time, and it's hard to get comfortable with that. The idea of getting back in there in a room with a bunch of funny people and just cranking out jokes is just really appealing to me."

For a while, it was rumored that Stewart, who played the part of a talk-show-host-in-waiting on "Larry Sanders," might get to actually replace star Garry Shandling and keep that critically acclaimed show intact, perhaps even moving it to a broadcast network. How serious did that get?

"Very serious. I had moved in with Garry," Stewart gushes, for once unable to stifle a laugh. "No. There was a lot of 2 o'clock giggling. You know, 'What if we kept this going?' Luckily, everybody had the foresight to avoid an After MASH situation. I think everybody sort of understood this show was a gold-standard show, and it never really became serious."

Not that he absolutely rejected the idea of doing a sitcom. "I think the state of sitcoms is similar to the state of almost everything you can point to in this country," Stewart says. "Ten percent of it is inspired, 25 percent is competent and the rest of it is a synthetic-like material that's just filling out the system. I think you can point to anything and you'll find that breakdown."

So where does Stewart's Daily Show place on that scale? "I try to be as competent as I can," he says, "and hopefully the occasional glimpses of inspiration poke through." With his serious side poking through, I ask if he had any problems lopping off a segment of his ego to replace Kilborn after being leapfrogged for the Late Late Show job.

"Lop anything off my ego? You don't know me very well, do you, sir? There's nothing left to lop," he says, then gets unusually serious again. "One of the things about this business, I don't look at it as finite. So one person's success doesn't diminish yours or take away from your opportunities. Any time people you think are qualified and funny do well, that just inspires you to think, 'If I keep trying hard and getting good, I'll get opportunities too. I've been really fortunate in this business to have as many opportunities as I've had. So I don't want to be one of these guys 50 years later at a bar, a bitter old drunk. I hope to avoid that."

He's more likely to have to worry about doing The Daily Show for 50 years. This has the look of a good fit, and Stewart the jack-of-all-trades might wind up settling into this latest role for as long as he cares to occupy it.