Here is just one of several new phones that are WiFi only. These wireless Internet phones allow you to make voice phone calls anytime you are in a WiFi hotspot--yet another reason to sprinkle WiFi hotspots around your community.
I found this particular phone on the BroadVoice site, yet another Voice over IP startup that has inexpensive phone rates. Like Vonage, you get a little adapter box that you plug into your Ethernet hub/switch, and you plug a normal telephone into the adapter box--instant Voice over IP phone. You can take the box with you when you travel and make phone calls from your own phone number anywhere you can connect to the Internet.
One of the key drivers of VoIP technology will be this last feature, which is true number portability. In the future, we won't need to keep track of cellphone numbers and home phone numbers, or cell numbers and business numbers. We'll have a true portable phone number that we carry with us in our pocket, literally.