Borat

This sociable Eastern European journalist is just the kind of person to make any conversation completely and irredeemably awkward. The second-stringer on "Da Ali G Show," Borat is the bumbling, girl-happy invention of Sacha Baron Cohen, who also plays hip-hop goofball Ali G and Bruno the Austrian homosexual. Unlike Ali G, who comes off as clueless, and Bruno, who only upsets homophobes, "Borat" will say whatever's on his mind (in one of his more famous moments, he asked a Texan rancher whether his African-American butler was his "slave"). If Borat asks to interview you, politely decline. And maybe get in touch with your lawyer, just in case.

Stephen Colbert

Now that "The Colbert Report" has become an overnight success, we have less to fear from America's favorite fake reporter. His mostly in-studio program is geared toward making only pundits and celebrities uncomfortable. But you never know when Colbert will return to the streets, doing a stint for "The Daily Show" and interviewing a repo man or a video store owner who rents only G-rated movies. The ace of deadpan, Colbert will ask anybody anything, and he's impervious to cracking up. The only thing crueler than Colbert's interviewing tactics is the way that his pieces get edited together -- maximizing the dryness of his reactions and the absurdity of his subjects' answers. If "The Daily Show" knocks on your door, mention your latest movie and ask for a guest-spot instead. If you're not a movie star, consider getting an extra padlock.

The Cast of "Jackass"

Famous for their merciless pranks and insane daredevilry, the Bam/Knoxville/Steve-O collective are some of the most feared human beings in show business. Don't loan them your car (they'll destroy it), don't go golfing with them (they'll flip their cart) and don't travel to Japan with them (god knows). It's unwise to accept food from them, travel in a van with them or even talk to them -- and if you spot them with a shopping cart, duck and cover. If you're related to Bam Margera, your life is already ruined; at the very least, don't expect consistent sleep patterns. Crazy, perverse and brilliantly destructive, the "Jackass" crew is bad news for the ordinary pedestrian -- and the most likely to cause bodily harm.