T-Mobile rolled out the @Home service in Seattle area stores this week. @Home is T-Mobile’s brand name for Universal Mobile Access that allows a cell phone to make voice or data calls using a pre-approved Wi-Fi hotspot instead of using the cellular network. In order to use @Home, you would need a compatible WiFi phone from T-Mobile. The currently available phones that work with this service are the Nokia 6136 and Samsung T709. The @Home service costs $20 per month for unlimited calling and is expected to launch in additional markets soon