phonescoop.com
Straight Talk
They are an MVNO in the US.
http://www.straighttalk.com/AboutUs »
Straight Talk is a service provided by TracFone Wireless Inc., America’s largest no-contract cell phone provider in the U.S., with over 15 million subscribers. TracFone Wireless is a subsidiary of América Móvil S.A.B. de C.V. ("AMX") (BMV: AMX; NYSE: AMX; Nasdaq: AMOV; LATIBEX: XAMXL), the fourth largest cell phone company in the world with more than 200 million cell phone subscribers.