Can you flash a sprint iphone 4s to another service?

I bought the iPhone 4s on eBay (the iPhone is from sprint) and I have metro pcs. Can I change my old phone and replace it with the iPhone that I bought?

For now, if you can find someone that can flash it to MetroPCS, yes you can. At least until T-Mobile shuts off the CDMA service, then your phone will be useless.

There's more to it than flashing though, you'll still have to get MPCS to activate the phone on their network for you, which will probably cost you some money.