Over one-third of U.S. high school students now own an iPhone, according to the latest Piper Jaffray semi-annual survey of U.S. teenagers. As reprinted by MacRumors, the survey found that 34 percent of surveyed students now own an iPhone, representing an all-time high and double the percentage seen just one year ago. In addition, 40 percent of those surveyed indicated that they plan to purchase an iPhone within the next six months. As for tablets, 34 percent of students said they own a tablet, and 70 percent of those said they have an iPad. 53 percent of iPad-owning students also own an iPhone, and 19 percent of students said they plan to purchase a tablet within the next six months, with 80 percent of that group planning to purchase an iPad. The survey was conducted among 5,600 U.S. high school students.