What is the chapest way to call to foreign home phone from prepaid cell phone or through internet?

I have only pre-paid cell phone and internet acces, and I do not have a home phone. My parents in Japan, and they do not have a internet access. Is there any cheap way to make a call to them through internet or from pre-paid cellphone? I do not have money to contract to home phone or monthly cell phone... so I have to call their home phone... Thanks!!

download skype.com and it is free to call anywhere to a home phone from your computer

I know you don't have a home phone but the best thing I have found is to by pre-paid phone cards. You can use pay phones to call the access number. The best site to buy cards for international phone calls is discall.com. Good luck.

If you have High speed internet--check out Packet8, Vonage or Lingo. Skype is excellent, also. With the voip phones you pay one price for the month..unlimited calling. Google these and see if that helps.

Usually you can buy prepaid phone cards and they are much cheaper than using a prepaid cell phone directly. They use an 800 number and will tell you how many minutes you can talk. They can be purchased from gas stations, or small international grocery stores usually.