Which cell phone companies have SIM cards that work in the US and Mexico?

T-mobile, Alltel, Cingular/ATT,


basicaly any GSM phone (best if tri-band)

Which cell phone companies have SIM cards that work in the US and Mexico?
I know T Mobile has coverage in mexico and i believe AT%26amp;T does as well. With T Mobile you have to activate the international roaming before you can use it outside of the U.S. Its free to have the international roaming with T Mobile, you only get charged when you use the phone outside of the U.S. I have several phones that I offer through both carriers. Oh and make sure the phone is either a world phone or is a quad band. Other countries use different bands than we use to transmit cellular signal. here is a link to my store





http://www.inphonic.com/autocontent.aspx...





I hope this helps

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