Accodring to the picture I had, top 7:
Sean Bean - 68% (Played Boromir in LotR and Harry Mason in the upcoming Silent Hill movie)
Alec Baldwin - 61%
Takeshi Kaneshiro - 59% (Japanese-born, appears in a bunch of HK movies, including a few of Wong Kar Wai's)
Ernest Hemingway - 57%
Barbra Streisand - 53% (roflcopter)
Charles Bronson - 53% (FUCK YEAH)
Clark Gable - 51%
I'm not bored enough to post a picture of an actual celebrity and see how close they match up to themselves. Maybe later, if I'm really bored.
EDIT -
It thought Ice Cube was Eddie Murphy.
It got George W. Bush right.
It got Arnold Schwarzenegger right.
It thought Josef Stalin was Nils Gustaf Dalen, a Swedish Inventor.
The pictures I had of David Hasselhoff and Gary Coleman were too small. Same for Alex Winter and Keanu Reeves.
It got Osama Bin Laden right.
It got OJ Simpson right.
It thought Vin Diesel was Rajiv Gandhi.
The only picture I had of 'The Macho Man' Randy Savage had him wearing dark glasses, so I think that was a problem.
It got Rudy Giuliani right.
Not all the pictures I had for it to test were 'ideal'. That's also just a quick poll of what I had on my drive here at work. I'm no expert, but I'd say 75% isn't terrible in cases where it actually made a call one way or the other. It's pretty easily broken, though.