Phone number porting is available starting today to all Google Voice users, according to the official Google blog. This will allow customers who pay a $20 fee to switch their current mobile number into service as their Google Voice number, allowing it to ring on multiple devices, including on a computer.

Number porting had been available on a very limited basis for some time, and Google opened it up to the public for testing only a few days ago. With today's announcement, porting of mobile numbers is now officially widely available, taking up to 24 hours to complete the transfer once initiated.

Once your in-service number is ported to Google Voice, your mobile contract will be cancelled (with all the fees that that implies). But when the porting period has passed, Google notes, you can begin a new contract with a different number and sign that number up to ring under your old mobile number that is your new Google Voice number. It's like nothing ever happened! Well, except for that early termination fee.

We're guessing the old rules for landline-to-wireless line transfers apply here (that is, only a select few are eligible), so this may not be the solution you've been looking for to get rid of your home phone without the attendant hassle. Still, for avid Google Voice users and fans, this may be worth looking into when the end of your mobile contract's days roll around.