dtsm and JP, thanks for the Tracfone and TMO information - it's a great help! I'll check if their coverage is good where I'll be traveling.

Yes, I want a SIM only for domestic (US) use. And I want just a SIM, not another handset.

If anyone knows about documentation required for a prepaid or pay-as-you-go plan, I'd appreciate any tips. I've only ever signed 2-year cell phone contracts in the US before, when I had proof of a US address. This time I'll have just a passport and visa.

If there are any security regulations that could make it difficult for a foreign visitor to get a SIM cards, I'd prefer to add international roaming to my current plan before leaving my country.

moe