i got this iphone for xmas and i want to get service for it without having a contract can i do thhat

It many places, including the US, Yes.

Here is a list of supported carriers: http://support.apple.com/kb/ht1937

Talk to one in your country and see what's available.

In the US, AT&T is the only supported GSM carrier. They will not allow you to use pre-paid plans on the iPhone, but they do have post paid plans that are strictly month to month and can be cancelled at any time.

That depends on where you live and the service providers. And is the phone one that is locked to a carrier? You need to talk to the carriers and see if any offer non-contract plans and if your iPhone will qualify and work on their network.