Becomes last major U.S. carrier to do so.

Cingular Wireless at long last has introduced a ringback tones service, becoming the last major U.S. wireless carrier to do so.

Dubbed Answer Tones, the Cingular service allows subscribers to replace the standard ring sound with an audio clip that those calling them will hear while waiting for the line to connect. The service costs $1 a month, plus $2 for each tone purchased.

While all four major record labels are licensing music to the service, Cingular and Warner Music Group teamed on a special category called “Say My Name” tones. The category features voice tones recorded by several WMG artists that include personalized greetings for certain popular names, such as Bill, Brian or Todd.

In other ringback tone news, Verizon Wireless has added a recommendation “personal DJ” feature to its service that suggests other songs to customers based on their prior ringtone or ringback tone purchases. The carrier has accumulated 10,000 tracks since it launched its ringback tones service a year ago.