The Seniors Coalition in Washington says almost half of Americans have used their cell phones in emergency situations, but millions of U.S. senior citizens -- who might benefit the most from the technology -- do not due, in part, to a lack of awareness about such low-cost options as prepaid cell phones.

Nicholas P. Sullivan, author of a study based on more than 110,000 interviews with cell phone users, says that 38 percent of America's 45 million poorest households -- including millions of seniors -- are without cell phones. Those who do not now own a cell phone tend to be older -- 37 percent are retired -- and low income -- 38 percent make less than $35,000 a year.

The Seniors Coalition advises older consumers to "wear" their cell phone because it will not do anyone any good if the cell phone is on the table a person falls down the basement stairs or gets mugged in an alley.

Family members should pre-program the cell phone -- or parent's cell phone -- with key numbers -- including home, doctor, pharmacist and family contact.