I am planning on visiting Cambridge, MA for 3 months from Japan. What’s the best prepaid cell phone for me just for 3 months in that area? I would be using my cell only for local call for less than 30 min. a month, no text, no e-mailing, no web surfing. As far as I research, Virgin Mobile is good? Or Trac Fone?? Any other prepaid phones you would suggest?