When I was a child, I wasn't allowed to have a phone in my room. Now most kids are given cell phones around middle-school age. Many more get them even younger.

While giving your child a phone is supposed to relieve the stress of worrying where they are and how they can reach you in an emergency, it also creates a whole new level of stress: How do you restrict their use while still letting them have fun? How do you stop them from running up enormous bills? And how can you best use the cell phone as a tool to keep your kid safeand not as an electronic leash?

The good news is, the major carriers (plus one that's not so major) have features letting you setcontrols on your child's phone use. The bad? In most cases, it's going to cost you.

AT&T and Verizon offer plans where parents set the times of day the phone can be used, make lists of allowed and blocked numbers, restrict web content, and limit the number of text messages sent; Verizon also allows limits on minutes. Unfortunately, those options cost $5 a month extra.

Sprint will give you all the same stuff for free, and T-Mobile provides similar services but doesn't disclose pricing on its website.

Another feature that could give a worried mom peace of mind is a "family finder" for GPS phones.Each of the carriers call it something different, but basically it allows you to find your family's phones instantly. It also lets you check their location at various times throughout the day, and a few will send emails if someone changes location -- like when your son arrives safely at after-school soccer practice or your daughter hops in her friend's mom's car for a playdate. They range in price from $5 per month with Sprint to  $14.99 with AT&T. And, much as I hate to say it, if you have reason not to trust your children to be where they say they are, this could be an excellent way to check up on their whereabouts.

There's one more alternative geared toward even younger kids: the Kajeet phone. It has similar features to the bigger carriers' plans with a couple of important differences. For one, you can block text and picture messaging entirely. You can also set "wallets" that allow you and your child to have accounts. If your child, say, goes over her minutes or just has to have that cool ringtone, she can pay for it with her money instead of it getting lost in the shuffle of your bill.Their parental controls are included, but their locating service is 99 cents per time or $7.99 per month for all but their top-tier plans.

How much will all this cost? Depends. The big carriers have family plans that include two lines, while Kajeet offers only individual ones for kids. The starting point for each, including voice but no messaging or data, is as follows:

AT&T: $59.99 for up to three lines; 550 minutes

Sprint: $69.99 for up to two lines; 700 minutes

T-Mobile: $59.98 for up to two lines; 1000 minutes

Verizon:$69.98 for up to two lines; 700 minutes

Kajeet: $4.99 for 10 minutes of talk time

Does your child have a cell phone? What kind of plan do you have?