Following the directions linked above to Lifehacker will enable you to obtain a US number from SipGate just for calls to send and receive calls from your computer for free. There is one issue with getting an account with SipGate: they require you to have a US number to for verification purposes only. They will send you a confirmation code essentially to make sure that bots are not signing up for the service. An easy walk around was having them send the confirmation code to my dad's phone and he simply IM'd me the code.
Note: The following no longer seems to be the case.
I will start this guide assuming you have already obtained your US phone number from SipGate and have set up a Google Voice account.
- Texting: once you have obtained the number assigned to you by Google Voice, you can now text anyone in the States and they can text you back. There is no charge sending texts to them and they are charged the cost of a domestic text. In other words, if they have an unlimited texting plan, they will be able to text you under that plan.
- Phone Calls: you will be able to make calls for free as long as you have the SipGate client open on your computer. Folks in the States will be able to call you at your Google Voice number and it will be forwarded to the SipGate client on your computer.
- Download Fring here
- Once the application is launched, choose a Fring user ID and password. These credentials are only for logging into Fring.
- Once logged in, go to the settings menu and select Add-ons. After being presented with the accounts you can link to Fring, select "Sip".
- To link Fring to SipGate, Go to your SipGate Account page and click on the SIP credentials link. There you will find the information you need to enter into Fring. Enter in the unique SIP-ID and SIP-Password and sipgate.com for the proxy into Fring. Click login.