Participants in this 1-year open-label study will be recruited exclusively via the internet. Participants will be randomly assigned to receive internet-based messages from either the Youthnet program or the control program. Messages from the Youthnet program will be interactive and tailored specifically to HIV/STD risk reduction. The control program will deliver standard STD/HIV prevention messages. Participants will be assessed at baseline and a follow-up session 4 months after enrollment. Frequency of condom use and attitudes toward condom use will be assessed using behavioral scales.