T-Mobile USA is planning mobile phone handsets that can roam on Wi-Fi hotspots, reports Reuters citing WSJ. “The new service, known as Hotspot at Home, has been in trial in Seattle and is expected to be launched nationwide as early as mid-June”. Details of the effort are here—the handsets will allow calls over Wi-Fi, but only at T-Mobile hotspots. The company seems to be focused on promoting “unlimited calls at hotspots” (which is fair enough considering calls are still the primary use of mobile phones) but I see no reason why it can’t provide a good, cheap data channel for content, especially large content files.