Technological Gadgets

One of the rules in the school I work in is " cell phones must be kept in the students lockers and turned off". Many of our student's travel with these items anyway. They can not have that technology in their backpacks and not be tempted to text everyone in the known universe. I often wonder at what age are our young minds mature enough to have technology at their fingertips during a school day to be used for educational and not recreational purposes?
I would love to use laptops and pod casts as learning tools but I am hesitant because I don't know if it will do more harm then good!