Ditch the landline or cell plan?

You can have the best pure Google smartphone and not have to pay for phone service, only data.  The caveat is that you will to be on wifi to receive a call. But, ah ha! You can bring your own wifi wherever you go. You can get a device called a MIFI or personal hotspot from Verizon or AT&T or whatever mobile provider you want. Keep in mind that Voice over IP uses about 1.2MB per minute. So if you use about 1000 minutes a month you'll use at least 1.2 gigabytes of data.  That's assuming all calls are actually going over the MIFI. If you're like me and have wifi at home and work you'll use much less mobile data.

If you just want to replace a home phone with a smartphone that makes calls over wifi. You won't need a mobile plan or MIFI.

Here's how to do it.

1) Get a Google Voice phone number.
2) Go to the Settings page in Google Voice. Make sure Google Chat is checked on the Phones tab.

3) Install Talkatone on your Android or iOS device, or both. Yes iPad and Android tablets work.
4) Start up Talkatone and use the same Google account as your Google Voice account.
5) Done. Make and receive calls using Talkatone.

If you are using a tablet or don't want to do speakerphone only calls pick up a good pair of earbuds with a microphone, a bluetooth headset, or one of these wired or bluetooth handsets. (Click em to find them at Amazon)

Edit: Yes, you can send and receive SMS text messages this way. MMS (picture or multimedia messages) do NOT work and will be silenty dropped and never reach you. Google is already working on this and has some support for people sending MMS to a Google voice number.  MMS originating from other providers, not

Edit2: Saving power. This could bite you.  Most, if not all smart phones will turn off WIFI after inactivity. This means you will not receive calls once it is disconnected. That's kind of a bummer since forcing WIFI to stay on will eat your battery.  So, clearly this solution isn't perfect.

Edit3: Upon investigating the talkatone website there is a setting that will keep the wifi connected.