How much does it cost to use an unlocked iphone in Europe?

I'm thinking of going abroad and I'm confused… If I unlock my iphone, does it cost anything more to use the phone other than what I've been paying each month already? So will I be able to text/call people in the US like normal without additional charges?

Not much, you will just been charged for unlocking alone… As far the Iphone unlocking is concerned, remote unlocking method serves best and cheapest mean… You can get this service from any commercial vendors online like http://www.mobile-unlocker.com.Other than that you will have the same plans as you have in your phone that depends upon the carrier you choose abroad.