Pret A Manger, a chain of upscale quick service coffee, bread, salads and sandwiches in France and The UK has adopted VoIP to their DSL platform in the UK.
While they are doing this for internal cost reductions and improved communications, it is similar to what Starbucks has done in the USA with T-Mobile for the data transport side of the business.
It begs the question. Is WiFi next for Pret A Manger? Or better yet, is Starbucks going VoIP? The latter would be interesting.