Hayden Panettiere

She's the youngest and most famous girl on this list. What she lacks in natural beauty she makes up for in jail bait-ednes...I mean the cheerleader outfit is half the fantasy, right?

Evan Rachel Wood 

This 20-year-old is the perfect combination of naughty and nice. She's like Nabokov's "Lolita" mixed with a dash of Goth. She loses points for letting Marilyn Manson pound her every night, though. That's rather unfortunate of her.

Gemma Ward 

She's one of the top supermodels in the world and she's only 20. That means looks, money and fresh meat.

Sasha Grey

The best-known of the under-21 porn starlet crowd, Ms. Grey is also retardedly hot. She's also a natural born hustler...she makes tons of movies every year and poses for foul-natured, unsafe for work pictures by the truckload. You gotta love her. 

Katrina Bowden

This "30 Rock" star is just plain adorable. She's freshly 19 and guess what? She's actually funny!