I just got one of the Toggle Mobile SIMs that have been discussed here. I ordered it from an Ebay seller in the US, but I believe Toggle Mobile will send them to the US on request.

One thing I discovered playing around with it is that while you can pick local numbers in all of the Toggle Mobile countries, you can always get your incoming calls on the UK number, with no charge from Toggle for incoming calls in 20 countries (including the US.)

Voipyo is one of the Finarea/Betamax calling services (doesn't matter if you don't know what that means.) Currently, their rate to UK mobiles is .5 Euro cents per minute.

With Voipyo you download a mobile app called Mobilevoip, and input your Voipyo credentials. The app will put your calls through as a pure VOIP call using the data network, by dialing a local number which will then transfer you to your desired number, or by triggering a callback. If you use the callback feature there is a 5 cent setup fee.

So, some scenarios:

• People can call you using Mobilevoip/Vopyo on your Toggle SIM for half a (Euro) cent per minute, with no charge to you
• You can use the callback feature to call you on your Toggle phone and call the US number (or any other number) that you want to call. In this case, you would pay the 5 cent setup fee, half a cent a minute for the leg to the Toggle phone, and no cost for the US leg of the call which is now free from Voipyo. Bear in mind that you can trigger the callback from the Toggle phone itself or another phone - I frequently travel with a smartphone for data only and a small dumb phone with a SIM that I use for voice calls (better rates.) (I think it is always a good idea to consider two phones for travelling; frequently the SIM that is better for data is not better for calling, and also having the data phone allows you to trigger a callback to the cheaper SIM.)