As well as enabling free PC-to-PC and PC-to-phone calling, Google Voice allows a single phone number to forward - through the magic of the internet - to several other numbers. This means that a PC, landline and mobile could all ring whenever your Google Voice number is dialed, making you accessible no matter where you are.
Unfortunately, this mean setting up a new phone number, and making sure you tell all of your friends what it is. Now, though, the search-giant has introduced 'number porting' to the service, allowing you to use an existing mobile number with your Google Voice account.
The process works a lot like transferring a number from one mobile network to another once your contract runs out. What this does mean is that your existing mobile contract will be terminated, potentially exposing you to nasty early termination fees from your old carrier. Worse still, you then have to go and get a new service contract if you want Google Voice to be able to forward calls directly to your mobile.
There are a few other caveats as well. Porting a number will cost $20, and the option is only available to existing users at the moment, although it'll be made available to new users in the coming weeks.
Obviously, the biggest drawback is that the full Google Voice service is currently only available in the US, and there don't seem to be any plans to expand to international territories just yet. For those interested, more details on the porting process are available on the official help pages.
