Wireless text messaging is a technology that was effective in improving medication adherence in clinical trials of vaccines and smoking cessation in Spain and South Africa (20,21). Text messaging has also been found to be more effective than telephone call-backs and scheduled clinic revisits in providing patients in London with lab results and decreasing the time for them to return to clinic for treatment (22). Cell phones have more recently become widespread in America and cell phone use continues to increase. A 2005 survey of wireless providers revealed that there were nearly 208 million wireless subscribers in the US, nearly 26 million more than in 2004 (23). Americans use cell phones for more than talking; they can use the text message function to share photos, to vote for reality television programming contestants, to receive daily jokes or to receive ring tones. Sixty-four percent of teens with cell phones use text messaging (24). Urban teen girls are more likely to use text messaging than boys or adults (24).