I need to make a phone call from Japan to America. It's even a toll-free number (maybe that doesn't make a difference since I'm calling from Japan), but when I tried to use my cell phone to call (I have Japanese phone service because I am living in Japan, not visiting) I got an error message. Maybe I need to enter 81 before I dial? And in any case, this may not be the best way to do it, because overseas calling is expensive (even though I have an app ("050 plus") that reduces call cost, at least domestically) and this call will probably take a good 10 minutes. Should I buy Skype credit and use that instead?