Where can i buy an iphone without a contract?

No contract, or service. Ill be using it pretty much like an ipod for a few months and just put it on Wi-Fi to use the internet and everything, then in a few months i can connect it to service. My ipod is pretty broken and really old and no i won't go get a new ipod because i also need a new phone, but my contract ends later in the year. So i need it to use for my internet (on Wi-Fi) til november. Is there anywhere i can just get an iphone with no services or contract on it to use pretty much like an ipod for a little bit? At a good price as well, as cheap as possible please, thanks.

Added (1). Id prefer an iphone 4 or 5

http://store.apple.com/...d-unlocked

Select the finish
And go to the tmobile and sim free area select the size and choose sim free

Craigslist, eBay, Amazon.

Apple sells the phone unlocked, no contract but it would need to be activated in order to work. You could take out the SIM after the activation. Wouldn't be a 4 or 5 though since the 4 is no longer sold in the US market (assuming that's where you are) & the 5 is no longer sold period, so it would have to be the 4s, 5c or 5s.