Can i replace the sim card in my iphone for a net10 sim card?

I don't want the whole plan thing, and I have had a prepaid phone, and I like paying for it monthly with the card because I don't want to have to go through all this trouble of putting the money on my credit card. Anyway can I just get a net10 simcard and put it in the iphone 4g that i'm getting? I don't care about the cost of the simcard. I just need a yes or a no.

Yes, but only if the phone has a clean ESN. If it is still under contract, or has been reported lost or stolen, it will not work.