I don't know if it will help. Kids are going to see ads for "cool" ringtones and screensavers and fall victim, imo.
I only buy the ringtones that are sold through my carrier ... they cost about $1 or so and I have about 5, which were bought over a period of time. Helpful for screening calls when I'm in the car and can't look at the phone. I know who's calling and can choose to answer or not.