You’ve waited three years to move your iPhone from AT&T(T) to Verizon(VZ) for whatever reason.  But perhaps instead of heading directly to Verizon, should you free yourself from the carrier lock-in altogether and add a lot of functionality and freedom for a small price?  You might even save yourself some time at Verizon dealing with the number porting.  Starting fresh is so much easier.  Here’s a short video on what will be happening if you choose to port your number to Google Voice first:

[youtube=http://www.youtube.com/watch?v=NdQmGLjvMGo&w=600&h=375]

Google (GOOG) Voice requires a one time fee of $20 to port your number.  If your carrier/plan require and Early Termination Fee (ETF), you’ll need to add that in as well.  But you were already leaving, right?  If you can handle those fees, Google Voice offers many benefits:

1. Make and receive calls right from your Gmail account.  This will cut down on your carrier minutes and make it easy to make calls to numbers in your contacts and within emails.  Google won’t charge you for calls to the US or Canada for the rest of 2011 and their International Fees are often lower than Skype’s.

2. Voicemail transcription and retention.  Before your call ever makes it to your limited carrier voicemail account, Google takes it, runs their industry leading voice recognition software on it and pulls out the transcript (seldom exact, but usually legible, sometimes hilarious).  That transcript and a link to the voice file are sent to either your email address or an SMS on your phone.  Google keeps your voicemails for as long as you want and they are searchable.

3. Recording.  Record any call and have it sent to your Gmail inbox with a push of the 4 button during a call.

4. Transfer calls mid sentence.  You’ve finally gotten to your desk and want to transfer the call from your cell phone.  Easy with Google Voice.

5. Have your calls ring anywhere.  Up to five different phones.

6. Route calls by caller.  Your work and family ring your cell phone, everyone else goes to voicemail?  Announce yourself?  Special messages per person.  All there, all free.

Sounds great?  How do you do it? TechCrunch’s MG Siegler chose to do this last week on the way to Verizon. It only took five minutes and he got a kick out of how easy it was to cancel his AT&T account.

First, sign up for Google Voice if you haven’t already here.

To get started with Number Porting, log in to your Google Voice account, visit the Settings page and click on “Change / Port” next to your Google Voice number.

You’ll then see all kinds of warnings on what is going to happen.  It basically comes down to this: your current account with your current carrier is going to be toasted.  ETFs are coming and expect up to 24 hours for the process to be complete.

Soon your number will be in Google Voice.  You can make and receive calls inside Gmail until your Verizon iPhone comes if you don’t have it already.  When you get your new phone with new phone number (pick an exotic area code just for fun!) just plug that number into Google Voice.  You’ll want to download the Google Voice App on your iPhone so that you can make calls with Google Voice.

That’s pretty much it.

I’d wager that the majority of people making the switch over the next few weeks would really get some utility from what Google Voice has to offer and there’s never a better time to jump on Google Voice than when switching carriers!