Robin Erlich of Nissequogue said she got her twin daughters cell phones when they were 8 years old so she could keep better tabs on them.

"I would drive one daughter to gymnastics and drive the other one to soccer," she said. "I wanted them to be able to get in touch with me."

Now Erlich is considering getting a newly updated service that will let her keep track of their whereabouts through GPS when they carry their phones, in case of an emergency.

"I don't think I would use it to spy on them or anything like that," said Erlich, of daughters Leviah and Ilona, now 10. Noting that Leviah had lost her iPod, she said, "If she loses her cell phone, then we'll be able to find it - and find her."

In addition to tracking services, parents have more options for keeping track of their kids' phone usage.

Verizon Wireless last week updated its Chaperone tracking service, which notifies parents via text messages whenever children leave or enter designated geographical zones. The service, which Verizon Wireless first rolled out two years ago, now allows tracking of up to four children at a time and viewing locations on a map online. The navigation service costs $9.99 a month per line and can be used to get turn-by-turn directions to a child's location.

The carrier also has launched Usage Controls, which, for $4.99 a month per line, help parents avoid surprise charges by setting limits.

A child who reaches a threshold of voice minutes would be warned but would still be able to make and receive calls, which would be billed. A child wouldn't be able to send any text messages beyond the limit. Parents can restrict messaging to certain times of the day or block certain numbers.

With T-Mobile's Family Allowances, at an introductory rate of $2 a month for all lines, even after a child has reached the maximum for voice minutes and the service is cut off, parents can stay in contact through unlimited family plan features or "Always Allowed" numbers. Text messages and purchases of ringtones and games can also be limited.

AT&T's $4.99-a-month Smart Limits service restricts text messages and downloads, blocks certain numbers and limits the times of the day that the phone can be used for certain functions, but it doesn't set specific monthly limits for voice minutes.

Sprint sells a phone that limits calls to certain contacts and allows a parent to restrict Internet access.

Not every parent finds such services necessary.

Lynn Gambarelli of Huntington said she bought her son and daughter cell phones when they were 13 and 12, respectively, when she felt they could be responsible with them.

When they exceed their limit of 400 text messages a month - as they did this summer, she said, "They have to pay."

Gambarelli said, "I don't need Big Brother to shut the phone off."