Engadget has a post that says that Vonage hs formally announced their F-1000 802.11 VoIP phone. This phone will allow you to make and receive phone calls whenver you are connected to a 802.11 network. This phone is supposed to be available this spring or summer for about $100.
I wonder how well these will work. With the wired VoIP adapters, the firewall has to allow incoming connections. (Knowledge Base article from Vonage) I am almost positive that when use the 802.11 network, at a Starbucks for example, the firewall will not permit incoming connections. Maybe Vonage will have the new phone always leave an outgoing connection up, and use that when receiving calls.
Update:Â Here is a picture of the phone.