Knocked Up (Unrated)

Parents need to know that, like The 40-Year-Old Virgin, Knocked Up earns its R rating with drug use, strong language (it's constant, particularly "f--k"), nudity, and nonstop explicit conversations about sex. Teenagers will want to see it, especially if they saw Virgin. But be advised -- the main character and his roommates spend nearly all of their time high on marijuana, and the physiological aspects of pregnancy -- from conception to crowning -- are front and center. (On the bright side, after watching all of that, it's a good bet that teens will be much less likely to risk having unprotected sex and may even appreciate what their mothers went through to give birth...)