Buy Prepaid Minutes
One surefire way to limit your kids' talk time is to buy them cell phones with prepaid minutes instead of a monthly plan. Prepaid minutes are an efficient and effective way to teach beginning phone users about time limits. Once those minutes are gone, they're gone, and the phone won't work until you pay more money. Of course, you can allow your kids to purchase extra time with the funds they receive from their allowance or from doing extra chores around the house, but -- big surprise here -- most kids figure out how to limit their talk time once the threat of having to use their own money enters the conversation.