IPhone Payment Plan? Real Thing?

I saw that AT&T, T-Mobile, and Verizon are offering payment plans that split the cost of the phone over 20 months, but you still have to sign up with them for service. I'm looking for a payment plan for an iphone, but have it be unlocked so I'm not required to pay for the phone AND service if funds are short some months. Is there anything like this? I can't afford $600 down.

No, that is not an option.

You can buy it at full price, or sign a 2 year contract for a discount.