Zac Efron is one charismatic robot.

In a recent Onion article, the pubescent marquee headliner was lampooned as an assembly line production of Disney Channel scientists. His dead eyes, perfect body and status quo conformity place him in the upper echelon of the new Disney breed of money machine superstars. The Jonas Brothers, Miley Cyrus and Efron all have a special place reserved in hell as shameless corporate shills molded to promote a very particular brand of contemporary teenage behavior (the kind that involves mindless consumption), and although Efron is able to flaunt his marginal acting chops for the first time, 17 Again is still a bust.

The film first introduces the Disney golden boy as shirtless on a basketball court, shooting hoops in a transparent effort to echo his High School Musical star persona. Five minutes later, he inexplicably jumps out onto the court to join a cheerleading troupe's dance number. It's the kind of scene that one imagines a board of suits developing late in the writing process.

Suit no. 1: "We need at least one dance number with the kid before the opening credits."

Suit no. 2: "Bob, you're a genius. The little girls will be wetting themselves."

Suit no. 3: "Don't you think that'll come off as a cynical ploy for cash? Why would the kid just start dancing? It's kinda obvious if you ask me."

Suit no. 1: "Of course it is. But this chart shows that for every second this Efron kid is shirtless and dancing, our opening numbers will increase by $2 million. We'll be the number one movie of the weekend, easily."

Suit no. 2: "What's our competition?"

Suit no. 1: "Crank 2 and some Russell Crowe movie about journalism."

Suit no. 2: "You're a genius, Bob. Here's the checkbook, go ahead and write yourself the bonus you think you deserve. Number 3, you're fired."

The story of 17 Again is a classic body-switching fantasy in the vein of Freaky Friday. Mike (Efron) is the star of his ball team and preparing for the inevitable college scholarship on the night of the Big Game. Right before tip-off, his girlfriend Scarlet drops the bomb that she's pregnant, and Mike walks off the court and away from future fame and fortune to help raise the child.

He makes the responsible, morally correct decision and is rewarded by waking up 20 years later as a droopy-faced Matthew Perry. He's now a pharmaceutical rep who's constantly passed over for promotion, Scarlet (Leslie Mann) is divorcing him, his kids hate him and he's living with his Star Wars-obsessed best friend Ned (Thomas Lennon, providing the majority of the film's limited humor).

He's in a 20-year rut caused by nagging "what ifs"- what if he'd played the Big Game, what if he hadn't had children, what if he'd gone to college, etc. Obviously, what he needs is a mystical old janitor to transform him back into Zac Efron so he can learn a vague lesson about letting go of the past.

Sure enough, after an ominous storm, Mike wakes up and is magically 17 again. It's still present day and he must now pretend to be a stranger to those around him. (Why is it that no one, including his ex-wife and his basketball coach, seems to remember what Perry looked like as a teenager? Nevermind.) It's a plot contrivance meant to place Efron in a setting that will maximize his star appeal; instead of playing the unlikely perfect teenager, he's now bestowed with a literal superiority that's capitalized on to the nth degree. The intelligence, maturity and wealth of an adult with the baby face of Efron equals big box office bucks.

The whole thing is incredibly easy to dismiss, but the fact is that 17 Again actually isn't a terrible movie. The concept is trite, but it's executed with endearing sincerity by director Burr Steers. Steers, maker of the overrated but amusing indie dramedy Igby Goes Down, is obviously making his own bid for commercial viability, and the success of 17 Again will no doubt give him the freedom to move on to better, more expensive projects.

The film's main problem is that with the casting of Efron the entire project becomes suspect. The baggage that goes with the Disney Channel robot puts front and center a fact that filmgoers are supposed to forget while watching this kind of easily digestible garbage: this movie exists solely to take money from your wallet. Efron is nothing more than a cash machine, a cookie-cutter Ken doll engineered by the Disney scientists to put asses in seats, and his presence is a constant reminder of the film's true nature. It's okay for a movie to exist as a product to be sold, but good commercial filmmaking should be less transparent. It's the difference between casting a movie star and a porn star-- movie stars use sex appeal to gracefully sell you fake sincerity, porn stars crassly sell you what it is that you really want.

In the end it's all about sex, but most respectable people want to be tricked into believing it's not. Given the choice between a classy evening escort and a roadside hooker, most will choose the evening escort. Zac Efron is a roadside hooker.