Does anyone know how the new Hybrid phones work(I402, I502 or I902).

1. Do they use a Sim?
2. If so, is the Sim only to allow for use of the Radio or does it also provide the phone service.

I know Sprint is CDMA. I am assuming the phone is CDMA in itself and the Radio is by way of Sim.

Any insight would be great. I like the I902, but do not want to change my plan. I have been on the same plan since 2000 and I have found nothing close to what I have got.

Thanks...