T-Mobile

Pros: International roaming; plans to introduce high-speed EDGE data network; pay-as-you-go option.

Cons: Network coverage can be spotty in the United States; short weekend hours; all-digital network.

Where can I use this service? All 50 states; international roaming available in more than 100 countries.

What should I know about this carrier? T-Mobile offers the popular Sidekick phone/e-mail device.