Currently available on DVD: "Exit Through the Gift Shop"

In the enthralling Exit Through the Gift Shop, a curious, talkative Frenchman with pork-chop sideburns runs around videotaping everything -- his wife, his children, his friends, the customers at his Los Angeles clothing store.

Thierry Guetta isn't a filmmaker; he's just a compulsive shooter, and he doesn't go anywhere without his camera. When Guetta discovers that his cousin has a secret identity, Space Invader, and that he pastes small, tiled re-creations of the aliens from the classic video game in public spaces, he begins filming the man's nightly escapades.

Their antics lead Guetta to meet another street artist -- Shepard Fairey, now famous for the iconic Obama "Hope" poster -- and then another and another. After almost a year of filming, Guetta decides he is going to make a movie about street artists, who create their often illegal work in the middle of the night or in bursts of daring in daylight. Guetta feeds on the danger, the adrenaline; he loves the ride, the excitement. But he just shoots and shoots, never going over his footage, and crates of tapes pile up.

And then Guetta hears about Banksy, a British graffiti artist who has pulled off some of the bravest and most clever street art of all, including paintings on the Palestinian segregation wall (the film contains footage of Banksy on the day he pulled the stunt). Guetta uses every connection he has, but the highly secretive and reclusive Banksy remains out of reach. Everyone tells Guetta he'll never get him.

But in 2006, when Banksy (pictured here as he appears in the movie) visits L.A. and needs an assistant, Guetta gets a huge break. Until this point, Exit Through the Gift Shop has been a rollicking, informative look at the world of graffiti art and the people who make it, risking high fines and even arrest to fulfill their creative needs.

Once Banksy enters the picture, though, the movie begins to change. Guetta becomes an increasingly active participant in the street-art world, not just a documentarian. (There's absolutely riveting footage of Guetta and Banksy at Disneyland, where they hang an effigy of a Guantánamo Bay prisoner on the Big Thunder Railroad ride, a prank that leads to big trouble.) And when Banksy tells Guetta that he's filmed enough and should start editing the footage he's amassed, Exit Through the Gift Shop becomes another movie entirely  -- a provocative and absorbing exploration of what constitutes art, the creative process and the power of hype to triumph over talent.

The movie offers a tantalizing peek into Banksy's studio and his methods -- the never-photographed artist appears only in shadows and with his voice digitally garbled -- but viewers expecting a film devoted to his career will be disappointed, since Banksy's work takes a second seat to Guetta's unexpected (and scarily prolific) art.

Is Exit Through the Gift Shop the big hoax some have claimed? Is Guetta, now a successful artist known as Mister Brainwash who has had exhibitions in New York and L.A., simply the latest prank by an artist known for his mischievous streak? In this case, whether the movie is genuine doesn't matter (although I'm highly suspicious of the professional sheen of "madness" displayed by the edited footage Guetta shows Banksy).

What makes Exit Through the Gift Shop so fascinating -- and it is riveting, regardless of your interest in the art world -- is the eloquent way in which it illustrates how beauty and meaning really are in the eye of the beholder and how that eternal phrase still holds true: There's a sucker born every minute.