I've heard the ads for Net 10 but never paid any attention to them. Never heard about anything else that you mentioned.

1. You might want to look into getting a Verizon prepaid phone as Verizon has a deal with Skype and then use Skype to keep in touch with folks from Russia. I believe they are the only carrier in the US to have a deal with Skype. Answers to FAQs about skype mobile

2. Or, you can look at T-Mobile and be able to use their WiFi calling service, I believe they are the only one to offer WiFi calling. You can make and receive calls in the US for free; however, you can only receive free international calls on WiFi, you will be charged for placing international WiFi calls. You will also be able to make calls or surf the Web when you are in an area where there is a poor or no signal yet an open Wifi. Support: Wi-Fi Calling. T-Mobile also offers unlimited data and minutes. The only problem I see is that you would have to pay a larger upfront fee for their phones on the pay as you go or monthly plans compared to Verizon. Their monthly rate of $50 is competitive though.