College kids, stranded travelers, and Sex and the City stars aren't the only ones that consider a credit card their lifeline. The silver-haired set relies on plastic now more than ever.

A decade ago, just 18% of Americans over the age of 65 carried an outstanding balance on credit cards, according to SRI Consulting Business Intelligence. Today, nearly half of all card-holding seniors carry unpaid balances month to month.

Though their debt levels lag behind the junior set, the amount of money the elderly borrows is creeping upward. The average credit card balance for senior citizens is around $2,000, compared to the average balance of $3,224 carried by whippersnappers ages 25 to 34. And it's only a matter of time before their debt levels mirror one another. Credit Card Nation author Robert Manning told The Mercury News that the use of credit by senior citizens will eventually be no different from that of the general population.

It's not keggers or kicky Prada pumps driving Grams and Gramps into debt. Necessities such as prescription drugs and groceries -- and even doling out money to struggling relatives -- are behind the rising rate of debt among the elderly. With health-care costs on the rise, and interest rates on income-preserving investments such as CDs on the downslide, items that were once well within their fixed-income budgets have become unaffordable. And the picture doesn't get any clearer as the aging population lives longer, outliving their retirement savings.

For those whose income-earning years are but a fuzzy memory, it can be hard to find ways to cut back -- or earn more. And the temptations of borrowing are ripe -- especially if you own your home and have a good, long-standing credit history. Still, the same rules of credit management we preach to the young apply to senior citizens: