Since we mentioned the Futurephone free international calls service, a few similar services have cropped up. It looks like for the next few years, there will be a number of services that let you place international calls, just for the cost of a call to Iowa.
AllFreeCalls.net lets you call two dozen countries for free. Just dial 712-858-8094, and listen to the instructions. Dial 0-1-1, followed by the country code and the number you want to call.
FreePhoneCallz.com offers a similar service: dial (712) 945-4444 and follow the prompts.
These services are taking advantage of the Federal Communications Commission's Universal Service Fund, which helps telecommunications in states where the telecom infrastructure is lacking. The U.S. government pays these companies a small fee for every call that is placed from certain states — in this case, Iowa. A more detailed explanation of the scheme can be found here. Also here.