I just bought a used iPhone(the original) do I need a sim card to turn it on and use it like an iPod?
I just bought a used iPhone(the original) do I need a sim card to turn it on and use it like an iPod? I not planning on putting it on a carrier for a while. If I do need one where can I get one?

If the iPhone has been reset and when turned on shows the plug into iTunes graphic then you must have an active AT&T sim card installed in it to activate it.
Once activated you can remove the sim card and use the iPhone as an iPod.