Although the law states that your child may face forward in his/her car seat at one year AND 20 lbs., it is recommended for safety's sake to have your child face backward as long as possible- until he/she meets the maximum height and weight for the car seat's specifications. Read more by clicking the link above.
Update 4/16/10: I faced my son forward when he was about 20 months old.
Emily became a mommy on her birthday in July of 2008 to a wonderful son named Sam. She has since become rather obsessed with all things related to babies and baby items.