Two studies were performed to determine the relationship between cellular phone use and either reaction time or performance among college students. In the first study 60 undergraduates completed a computerized reaction time test. Mean reaction times were significantly higher when participants were talking on a cellular phone, either handheld or on a headset, than when they were not. In the second study 40 undergraduates steered a remote-controlled car through an obstacle course. Performance scores were significantly poorer for participants when they were talking on a cellular phone than when they were not. A majority of participants reported using cellular phones while driving, yet believed this was a dangerous practice. We recommend incorporation of education about cellular phone use and driving in health/safety curriculums for high school and college students.