Google Voice – Port your Existing Number for $20
The current price is $20.00 and you can port your existing number over. Of course if you are currently locked in a contract, you may get hit with Early Termination Fees so beware. If you aren’t and want to port your number over to Google Voice, login to Google voice and click settings, then from the drop down select Voice Settings, and select change/port.

Some users may not have access to this yet so if these options are missing from your account, I guess you will have to wait some more time for it to be activated.

Here’s the details and what to be aware of:

Congratulations.Your mobile number can be ported.

Things to understand before porting your number to Google Voice:
The cost of porting is $20 (payable through Google Checkout).
Your mobile phone service plan will be terminated when you port your number to Google Voice and your carrier may charge you an early termination fee.
Once porting is complete, you will not be able to receive calls to your mobile phone until you complete the following steps:

* Google Voice is not a mobile phone service provider, so you must setup a new mobile phone service plan (with your existing carrier or a new carrier) and request a new number.
* Once you’ve secured a new mobile service plan and a new number, you will need to add this new number to your Google Voice account as a forwarding phone.

You may be unable to receive text messages for up to 3 business days after the porting process is complete.
Your Google Voice number will be replaced by the number you are porting. It will remain on your account for 90 days.
I understand the risks associated with porting my number to Google Voice and want to continue with the porting process.