Alltel is joining the growing number of carriers that are embracing free calling plans, but the service it announced today, called “My Circle,” goes further than any carrier so far has taken the concept.

Alltel is allowing customers with higher-cost plans—those more than $60 a month—to select 10 phone numbers anywhere in the U.S., wireless or wireline, consumer or business, as a calling circle in which no connection or use charges apply, 24 hours a day. Many carriers have adopted free calling among phones on a family plan, free on-network calling to other customers on the same calling, and Sprint recently created a program that allows unlimited calling between a single home or business line and a wireless phone. But Alltel’s program is far more ambitious than the rest.

The service is available to existing and new customers and only requires registration on Alltel’s Web site with no additional charge if they meet the initial rate plan requirements. Furthermore, customers can change those 10 numbers anytime they like through its Web portal.