For example, Some companies have a plan where you can put money on your account and then you just pay $1.00 each day you use your phone and $.10 a minute. With with kind of plan, if you put on $15, it's only good for 30 days and then it expires, however, if you put $100.00 on the account, then it is good for 365 days. Your mom would not have to worry about adding funds, paying invoices, etc. because whenever she used the phone, the money would be deducted from the $100 she originally put on the account.

Other Wireless companies offers Impulse, which is very similar, however, the minutes expire after 120 days maximum (i.e., $150 or more expires in 120 days).

Some companies offers a "Spending Limit Program", where as long as you don't go over your predefined limit (i.e., you pay for your usage upfront), you are good to go. You are basically choosing from their plans and pre-paying and then as long as you don't go over…

Other companies offers a very attractive prepaid plan, where your bonus minutes don't expire for 1 year. You get more minutes added based on how much you put on the card. For $100.00, you would get 1,000 minutes added plus the minutes don't expire for a year.

So, I would start by looking at the coverage maps for the area that your mother lives in (or drives in) and see what provider has the best coverage. If some of the companies have the best coverage, I would suggest choosing one of these providers because I think they have the best prepaid plans (minutes that don't expire for 1 year). I would suggest that your mom put $100 on her account and then for the next year, she won't have to worry.

Have had a look at the deals that the company dose and they are very reasonable. If you do just want a phone for making an odd call a work or on the road then the Nokia 1221 would be perfect. It's a very simple phone with an airtime balance display. You get a coupon book that can save you loads on your future air time.

I would say in your case go to some of the stores around your area or some other retailer and check out the prepaid phones. All you do is buy the phone and pay for the minutes you use. To go out and get a contract would cost you at least $20 a month. Or you can get a prepaid card through what ever company. When you choose your cell phone it will say what company the phone is with or you could ask the sales person that is helping you and they will tell you.

Your best bet for prepaid cell phones in Japan would be the airport. There's almost certainly somewhere there to buy a prepaid cell phone.

I'm having a hard time coming up with links to other prepaid phone sites that aren't entirely in Japanese, but there should be plenty of places that sell them. However, you will likely need an alien registration card and your passport before you are allowed to buy one.

If you don't have an alien registration card, you might not be able to get one. If you are outside of Japan (which I doubt, since I think you just sent me another question), you can often purchase prepaid cell phones for use in Japan prior to your departure.

You usually have to find a store that is owned by one of the big phone companies in Japan to be able to get a phone that only works there. But most times you should be able to get a phone for Japan in the airport.