AT&T\u00a0is launching a residential voice-over-IP service that might be suitable for small office\/home office workers and telecommuters.Called CallVantage, the service melds flat-rate local and long distance calling with features including voicemail, call logging and follow-me. It was demonstrated for the first time Tuesday at the VON 2004 show in Santa Clara, Calif.By taking the customer premises equipment that comes with the service to other locations, customers can have the full function of the service wherever they can get a phone, computer and broadband Internet connection.Once they are signed up, AT&T sends customers a D-Link 1120 gateway that plugs into a PC, the broadband router or modem and to one or two phone sets.The phones work just like they do when connected to a traditional TDM phone line. To use service features, customers log in to the service provider's CallVantage Web portal. There they can set up conference calls for up to 10 callers, check their messages and trigger Do Not Disturb, a feature that sends all calls directly to voicemail for a set period of time.Customers can listen to their voicemail as .wav files and check their call log to see who has called them by phone number and by address. They can then click on the phone numbers to return calls.A feature called Locate Me stores up to five phone numbers and can forward calls to all of them at once or dial them in a given order to track down users when they are away from the primary phone.Users can phone in to an interactive voice response system that leads them through options that let them access some of these services. For instance, the IVR does not support setting up a conference call because, as an AT&T spokeswoman at its VON booth said, "It was cognitively too difficult."Because the AT&T network recognizes customers by IP address, they can take the D-Link CPE with them and plug it in to a different broadband connection, PC and set of phones and work as if they were at their regular location.CallVantage is available in New Jersey and Texas and will roll out across the U.S. over the course of the year. The service costs $20 for the first six months on an introductory basis and then goes up to $40. Customers must sign up for a year.The fee includes unlimited local and long-distance calls. International calls are billed separately.