I use the pre-paid roaming services when I travel to the USA. Roam Mobility is a new Canadian company that resells voice, text, and data plans from T-Mobile. You buy a SIM card (if you have an unlocked phone) or an international phone from Roam Mobility in Canada. They give you a new USA-only number. Once you cross the border, you swap SIM cards, and then make and receive unlimited calls and texts within USA and from USA to Canada. (Canadians can call your USA number, too.) Works out to about$3/day for text and talk; more for the data plan.
My daughter successfully used the Roam Mobility SIM card in her Android phone on a couple of recent multi-day trips to the USA, but with talk-text only.
Last week, I tried the talk-text-data plan on a multi-day trip to San Francisco. Problem was that I could not connect to the Internet (the data part of the plan). Fortunately, Roam Mobility support was still working at 8pm when I called for help.
It turns out I needed to create a new APN (Access Point Name) -- something Roam Mobility doesn't mention on their Web site nor in the booklet that accompanies the SIM card. APNs tell the phone how to access the carrier to get to the Internet.
Here are how to do this for Roam Mobility on an Android phone:
APN Configuration Instructions
1. Select Menu > Settings > Wireless & Networks > Mobile Networks
2. Ensure Data Roaming is unchecked
3. Select Access Point Names > Menu > New APN
4. Fill in the following profile fields:
Name: Roam Mobility
5. Select Menu > Save
6. Highlight the dot at the left of the newly created APN to activate the new profile.
7. Turn the phone off and back on again. Once you've regained connection and see an internet indicator of E, 3G, or 4G in the phone's status bar, attempt to go to www.google.com.