In my classroom, cell phones/iPods, etc must be placed in the box by the door as students enter. 
If students choose to ignore this policy & are found with a device,  their electronic will be taken to the office and returned after 24 hours. Student may also be issued a detention for disobeying policy. 

School issued technology (iPads & laptops) are to only be used when students are instructed to do so or they may use them after their work for the day is complete.