Noting two recent trends among youths, Clive Bates and Anne Charlton of Action on Smoking and Health in London formed an interesting theory, which they describe this week in the British Medical Journal: Could mobile phones be replacing cigarettes as means for teenagers to seem more adult and individual, socialize with one another, bond with their peers and just plain rebel? In fact, the numbers seem to bear that idea out. Between 1996 and 1999, smoking among 15-year-olds fell from 30 percent to 23 percent. In the meantime, cellular phone ownership among teens 15 to 17 years old rose from extremely low levels in 1996 to a whopping 70 percent in August 2000. Data on teen smoking are not yet available for 2000, but the authors expect to see even sharper declines. They suggest that for teenagers seeking a gateway into adult life, smoking may ultimately be seen as "old technology" compared to text messaging, e-mail and WAP.