"The fact that Sean Connery would keep showing up on Jeopardy to yell at Alex Trebek doesn't seem like it would be funny at all," says Hammond, who'll bring his stand-up routine to the Laff Stop this week. "It was so silly. But for some reason, [Connery] really registered with people." In one memorable game, Hammond-as-Connery asks Will Ferrell-as-Trebek for the category "Therapists" but mischievously pronounces it "the Rapists."

Hammond once did his famous Bill Clinton on stage with the man himself. "The Arkansas vowels of Clinton really got me. And he seemed to be 'doing' somebody himself. But that's his style of speech, and I've never heard anyone like him before or since," says the comedian. Clinton also has been something of a good-luck charm; just a few seconds of Hammond's Bubba impression won him his initial audition with the show.

One impression that resonated beyond the TV audience was Hammond's Gore, which he busted out in skits lampooning the presidential debates ("Put it in a lock…box"). When the real-life candidate's own advisers showed him clips of Hammond's robotic, staccato, wooden replica and noted that that was how he was viewed by many Americans, Gore made an effort to loosen up his image (though not so successfully, as it turned out).

On TV, the cast of SNL is an all-for-one theatrical troupe. But the audience doesn't see the week leading up to the broadcast, with the constant jockeying and multiple script changes that performers and writers go through to get their sketches aired. According to the definitive book Live from New York, even sketches done in dress rehearsal are routinely cut only hours later during the live broadcast, sometimes with the cast ready in costume and waiting in the wings.

"It's definitely competition, but not backstabbing," Hammond notes, "though you do basically have to audition [from scratch] every week." He doesn't perfect an impression before the writers work it into a sketch. Instead, it's just the opposite: He often has precious little time to get a new target down just right.

Even now, Hammond finds it "surreal" that huge superstars will be ten feet in front of him chowing down at the backstage buffet table seconds before stepping in front of the camera for millions on live television. "My brain tries to comprehend it…but it quits!"

Hammond is spending his summer break honing his stand-up act, which takes on the insanity of current events and politics (and yes, his dead-on impersonations are part of the show). Next month, he'll find out if he's going back for his 11th SNL season. If so, there's one impression he's got all set to go:

"Wolf Blitzer from CNN!" he shouts. "I keep watching him and going, 'Man, they've got to give me Wolf Blitzer!"