PAGER

I know Radio Shack used to sell them (pagers), and the service was about $10 a month. It was just a plain numeric display, no-frills pager. Unfortunately, pagers are quickly become fazed out.

There is also a device called the "Firefly", which is a phone, but only dials out to "mom" or "dad" or 911, thus eliminating the chance of racking up a huge phone bill.

You can see it here:

http://www.wirefly.com/zipentry.asp?cid=21427_200faadb9a4c4898b95d3a742c501bfa&referringdomain=wirefly&agent=&e=4&c=&p=&p2=&rp=&action=add&rpid=&p1id=&p2id=&p1pid=&p2pid=&rppid=&dest=&oflag=sfcart&pageid=0&ProductIDs1=&ProductIDs2=&FeatureIDs1=&FeatureIDs2=&CarrierID=62&phoneid=25325