There are no USA mobile companies who offer me this opportunity, but I found it somewhere else. Zain.
Zain Group ( formerly MTC or Mobile Telecommunications Company) is Multinational Corporation specializing in Mobile Telecommunications. Its area of operations include the seven countries in the Middle East, Kuwait, Iraq, Saudi Arabia, Jordan, Bahrain, Sudan ,and in Lebanon as mtc touch, and in 15 sub-Saharan countries in Africa Burkina Faso, Chad, Democratic Republic of the Congo, Republic of the Congo, Gabon,Ghana Kenya, Madagascar, Malawi, Niger, Nigeria, Sierra Leone, Tanzania, Uganda and Zambia. Free roaming in 22 countries!
Listed on the Kuwait Stock Exchange, Zain's market capitalization exceeded US$29 billion as at March 31, 2008. There are no restrictions on Zain shares as the company's capital is 100% free float and publicly traded. The largest shareholder is the Kuwait Investment Authority (24.6%).
Check out the milestones they have reached. Their most recent one...