When I ordered my iPod off Amazon.co.uk, I was offered free Amazon Prime for 1 month. I immediately signed up. This offer was available on check-out so I am not sure if everyone will be able to get the same free Prime delivery for 1 month.
Also you need to cancel the Prime before the closing date i.e. at least 1 day before otherwise you will get charged £47.00.
Also if you cancel the Prime but want to use it again during your free month I'm not sure you can do this because Amazon mentions it.