The service lets parents look at a map on their cell phone or computer to locate their children who also carry mobile phones. Parents can also program the service to automatically send them a text message at a specific time each day to confirm the children have arrived at home or in school.
The Family Locator service aims to bring in revenue from a location technology that Sprint and its rivals are required by law to put in cell phones so safety workers can pinpoint the location of 911 emergency service callers.
Sprint's service shows data such as street addresses near the child and the estimated accuracy of the reading, which could range from a radius of two yards around the child to a radius of hundreds of yards.
It also notifies children with a text message when parents have checked up on their location.
Walt Disney, which is renting space on Sprint's network to sell services under its own brand, said last week that itwith similar services.
Mobile packages designed for families have become the key to growth at U.S. operators, which have signed up as many as 60 percent of their new subscribers via family discount plans, according to technology research firm, Yankee Group.
Butin this respect, said Yankee Group analyst Marina Amoroso, who estimates Sprint has a roughly 12 percent share of the family plan market--less than half that of Cingular Wireless and Verizon Wireless.
"Sprint has essentially underperformed in that space. It does not have nearly as much market share," Amoroso said.
Because the Disney service, which launches in June, also lets parents control when and for how much time their children can use their cell phones, it will appeal to a different type of family, said Amoroso, who believes parents who just want location information may favor Sprint's offer.
But the $9.99 monthly service fee, and a slim consumer demand for people-finding services may limit Sprint's success at using the latest offer to boost its family customer numbers, Amoroso said.
"Before this service comes down in price, I think it will be marginal," she said, estimating that about 2 percent of U.S. subscribers are interested in people-locating services.
Aside from promising competitive prices, Disney has not said how much it will charge for this feature.
Sprint said its location service would work on 17 of its phone models and these phones could be used to locate children who use as many as 30 different phone models.
Sprint's biggest rival, Cingular, is owned by AT&T and BellSouth. Verizon Wireless, the second biggest U.S. mobile provider, is owned by Verizon Communications and Vodafone Group.