How much would it cost to activate an Iphone 4 for Verizon?

I bought an Iphone 4 and I want to activate it. I was NOT due for an upgrade but I couldn't wait another year with having an old flip phone. How much is the activation fee? Is it true I can activate the Iphone for free from my computer?

I already have unlimited texting and calling and whatever. Will having a smartphone add additional charges? How much more?

Free with a new 2 year contract

Please ANSWER MINE

It depends on the contractual arrangement you have with verizon it might be free if you sign up for a 2 year contract but that will lock you in