Where should I go to have Verizon Iphone 4 unlocked?

Hi,
I just bought a verizon locked iphone 4 from a friend and I am not sure what other carriers I would use it with but I might just send it overseas but before I do that I want to unlock it.
My question is where do I have it unlocked?
Does Apple offer that kind of services or should I talk to the carrier?
I know about jail breaking it, but how much does it cost to have it factory unlocked?
These are my questions
Thanks a million

You can't unlock a Verizon iPhone 4
this phone is a CDMA only device
it can only be flashed over to other CDMA networks, which generally those networks won't do.

also, you can't have ANY phone factory unlocked, this means the phone was never locked after coming from the factory.

Try appleunlocker factory unlock service for iphone 4:
http://www.monitoring-softwares.com/how-to-unlock-iphone.html