You can buy any phone and go on prepaid but it is going to cost you a lot more that way. You would need to buy the phone outright and then pay for your prepaid card on top. Whe you go on a contract it works out cheaper for the phone and usually they ...
Yes there is, have a look onto those below web sites : I hope it help. Cheerio.
Sprint doesn't use sim cards. They are a CDMA provider. T-Mobile and AT&T/Cingular are the two main GSM providers in the US, though there are some smaller companies that use GSM also. Boost Mobile also uses sim cards, but is an iDEN provider, not GSM...