Will any of your cellphones work in USA?
Attention:Some phones support GSM 900/1800/1900MHz tri-bands. Some USA Provider only support 850 mhz, and some of these phone May not work with them, please check with your local service provider (AT&T, T-Mobile may use 850 MHZ in some rural areas,make sure with your provider if your SIM card can support 1900MHZ before bidding. This phone works only with 1900MHZ in USA).
Were Can I check to see if your phones work with my carrier?
The following website contains most wireless providers and the frequency they use. Please compare with the phone you are interested to make sure it works with your carrier.
http://www.gsmworld.com/roaming/gsminfo/cou_us.shtml