Can i turn a sprint iphone 4 into a virgin mobile phone?

I just left sprint a few days ago and now i want to use prepaid and i was wondering if i can turn my iphone into a virgin mobile or any other pre paid phone companies

No, the iphone is only available on sprint, at&t, and verizon.sorry.

Yes, find someone that 'jail-breaks' phones, most towns have a little shop that does this, it is legal, but you have to pay a little bit, maybe 30 pounds

Sorry scrap the first bit Sprint is CDMA and Virgin is GSM, so no, sorry

You actually can its called "Flashing" Sprint and virgin mobile use the same towers. They are both CDMA.
here is a video of a sprint phone on virgin mobile.

you have to find a flashing service. What it does it basically transfers your IMEI to that phones service
but you cant just go to virgin mobile and say you want to put your phone on their service unless you buy the phone all over again, and in virgin mobile that would be at full price