I use one for emergencies or traveling too. I think I live in the only area of the US that doesn't have cell service so they don't work when I am home. It was stupid to be spending 30 a month on a phone I never used
Alltel has a good plan, your minutes are good forever, you only need to make a 1 minute call a month. It is either 10 cents or 15 cents a minute. and you can get a phone for $19.00. With the new cell phone laws you might be able to get them to reprogram your current phone and not have to buy a new one.
this is the Alltel U program and I use the pay per minute program.http://www.alltelu.com/pay-per-minute.jsp
They also have the pay per day and pay per month. The per minute for me is excellent. I got my phone last October and put the initial $20 worth of minutes on it and I still have $13 left.