This is a bit off topic but I can see how a WiFi phone and this service could work in many scenarios.
If retailers nearby Starbucks started to work with T-Mobile they could make all kinds of offers to the sippers who are surfing. If services that offered ordering by phone posted their offers this way people could get last minute type of deals.
Imagine the value to a travel related service wanting to hit high income families in once select city area, say Del Mar, CA because their past travel history shows that they love to fly to Mexico over Thanksgiving. With this service if excess capacity was available on some airline, and high end resorts had rooms a targeted Del Martian special could be served up. With a VoIP phone or a Skype address or anything like that, the person could call in and order or go online and order.
Huge !! This is the bulletin board of this century. All it takes is marketing smarts.