"He seems like an awfully nice young man," says the George Bush look-alike (poor fellow) to the Barbara Bush look-alike as a spindly dude zooms past the White House. Whether or not he's awfully nice, he is awfully funny, which is why Tommy Davidson got his own special on cable.

Of course, any comedian who can put two words together, and several who can't, get their own specials on cable. The Washington-born Davidson, a regular on Fox's engaging but uneven "In Living Color," deserves his.

Indeed, he deserves more than he gets. The special, "Takin' It to D.C.," at 10 tonight on Showtime, is only half an hour long. It was taped in April during Davidson's concert at Lisner Auditorium here. Thirty minutes must represent, at best, a third of the performance. Just when you're in a nice rollicking rhythm, it's over.

And the severity of the editing gives the show a chopped-up, splicey feel that doesn't help it at all, though it also means there are countless reaction shots of the crowd. Those who were at the concert and see themselves on the screen will be pleased.

Even if it's only a small sampling of Davidson's comedy, the special seems certain to expand his audience base and further his fame. He's a bright, buoyant comic who uses his slight frame inventively; bouncing around the stage in pants so baggy they seem inflated, he looks practically weightless.

His humor can be racy but it isn't dirty. His funniest routine -- at least among the few included on the tape -- pokes fun at Michael Jackson and certain of the hand gestures he uses in his videos.

After a breakneck opening sequence taped at various Washington locations (Adams-Morgan, Georgetown, the Mall), Davidson begins his performance with comments about Marion Barry. "We got a helluva mayor in D.C., don't we?" he asks, to appreciative jeers. From there he rambles on to such disparate topics as roaches and kids and his predominantly Latino neighborhood in Los Angeles.

Recalling the TV of his youth, which every comic does eventually, he imitates Scooby-Doo and offers evidence to support his view that Sugar Bear, the cereal mascot, was black. Davidson also impersonates Anita "arm-jive" Baker, Lionel Richie, and Prince as he might behave at a McDonald's in Queens. In case you were wondering.

Davidson has good material, and his ingratiating style elevates the content. Unlike some of today's comics, there's nothing sour or nasty about him. The crowd's laughter cheers him on, and you can share the pleasure he gets from them as well as the pleasure they get from him.

Tommy Davidson's heart is in the right place: his work.

'Dream On' Home Box Office has assembled an all-star cast for its new sitcom "Dream On," but the assembling was done in a film library. Great stars pop up, all right -- in black-and-white clips from the vault at Universal Studios.

Ronald Reagan, Bette Davis, Groucho Marx, Joan Crawford, Jack Benny, Vincent Price, Ed Wynn, Burl Ives, Lee Marvin and many others, living and dead, materialize. It seems the hero grew up watching television, and now his daily life is besieged by visions from long-gone TV dramas that pop up at regular intervals to derail his trains of thought.

That's the premise, anyway. The series, premiering on HBO tomorrow night at 10 (14 half-hour episodes have been filmed) does have a certain elusive entertainment value. The problem is that the little scenes from the old shows seem so much more intriguing than the new show they interrupt.

Early in the premiere, for instance, we see Barbara Hale (later Della Street on "Perry Mason") shrieking in horror as she watches Peter Lorre saunter down a hallway. Reason: He has an eye in the back of his head!!! Literally.

Gosh, let's see more of that! But no, we're soon out of the flashback and back to the story of Martin Tupper, a 36-year-old book editor who bumbles through life halfheartedly romancing his ex-wife and never quite asserting himself in a way that would make you want to give a hoot.

Brian Benben, as Tupper, has the dull anonymity of typical TV white bread. He could be Joel Higgins of "Silver Spoons" or Scott Bakula of "Quantum Leap" or some other modular shlemiel. The character is just about as indistinguishable as the actor is; the interrupting clips seem to have little to do with his persona. He's not Walter Mitty, he's not Billy Liar. He's just this guy.

David Crane and Marta Kauffman, the writers, put in some bright lines and funny touches, and occasionally the juxtapositions with the old film clips are inspired. John Landis, the creepy movie director, directed the premiere and co-produces the series, and did okay.

Some viewers will be cheered to hear that since this is cable, there are peeps of nudity. To be specific: two bare breasts per episode. On the premiere, the breasts are covered with whipped cream.

As for the clips, they're all from anthology dramas produced by Universal in the '50s and '60s, and thus can be used free of charge. Sometimes, indeed, they are maddeningly tantalizing, as when Peggy Lee opens the door and sees A Man With a Melted Face! Or when a woman jumps out a second-story window as a man on the ground yells, "Jane! No!"

The films look to have been beautifully preserved. Maybe somewhere in the distant cable future, say at 2 or 3 o'clock some channel-hopping morning, the excerpted films will air in their entirety. "Dream On" can be thought of as a preview of coming attractions that already came. And went.

It seems likely to come and go pretty quickly itself.