Hollywood's bad girls!

Keira Knightley
The Pirates of the Caribbean star celebrated her 21st birthday in style earlier this year, with a 1920s-themed, tequila-fuelled bonanza that left her #30,000 out of pocket. She invited 150 guests to drink over 150 bottles of Dom Perignon and Moet champagne, as well as her boyfriend's tequila cocktails, and at midnight a burlesque artist leapt out of a giant egg and sang Happy Birthday.

She recently revealed she likes to neck several glasses of wine a night and doesn't bother to watch what she eats. 'I'm trying to go 'F*ck it' and have bowls of pasta or whatever makes me happy,' she says. 'I haven't been to the gym since January and I'm drinking about half a bottle of wine a night. F*ck it, you've got one life - live it.'

Tara Reid
Although she recently claimed to have toned down her ways, American Pie actress Tara spent a wild night dancing on the tables at a nightclub in the Hamptons. She was reportedly getting down on the tabletops until she was 'kicked out' of the bar and then continued to a friend's house where she reportedly partied until 7.30 am.

Tara developed such a reputation for her drinking - and even a few breast flashes to the paparazzi - that she has become synonymous with the wild lifestyle. 'I'm not some Tara Reid-style party girl,' professed Lindsay Lohan earlier this year. 'I want to be in this business for the long run.' Ouch!

Sienna Miller
The Alfie actress caused a stir at the post-Oscars parties by allegedly behaving in a 'loud, childish' manner at the Vanity Fair bash. Notoriously straight-laced Hollywood was said to be unimpressed by her giggling and flirting.

She said she resents the extent to which her misdeeds are reported in the press, and seems to have calmed down since reuniting with old flame Jude Law. 'I wish (the tabloid coverage) wasn't in my life to the degree that it is or has been, but I accept that it has been a pretty tumultuous year and hopefully it will die down,' she said.

Scarlett Johansson
The gorgeous 21-year-old has had parties hosted for her by British royalty and been spotted in clubs in New York with fellow party girl Avril Lavigne. She also loves to play pool: 'When I was able to beat the boy-friend who taught me the game, it was the most exciting time of my life,' she said.

She showed she knows her own mind when she told Tom Cruise where to stick his M:I:3 role after he reportedly tried to convert her to Scientology. But her finest bad girl moment must have been when Scarlett reportedly got all hot and bothered in a lift with actor Benicio Del Toro back in 2004.