Ben points out that current technology makes VoIP over Wi-Fi a difficult proposition on a laptop in most hotspots. You know, multinational coffee giants, huge bookstore chains, and the like.
It will be interesting to see what business model comes as a result of this. I predict we'll see companies like Vonage, Skype and others push out VoIP over WiFi handsets, and then work with existing Wi-Fi hotspot facilitators such as Wayport and Boingo to push the technology as an optional service.
But if that happens, please don't spill that Mint Mocha Chip Frappuccino on your VoIP handset, K?