I am so glad my daughter has one. She only uses it for text messages as I have told her that putting it to her ear might result in a microwaved brain.
She is very good with it, never gets it out on the way home and we only live about half a mile from school. However, I work part time and on the days I work, she texts me that she is home. She also texts me if there is any problem, which is great.
Get him one. I can guarantee that he will be the only kid who doesn't have one at secondary school. I had reservations when I first bought it, but what the ****, you are only young once.