Unfortunately, many people are not taking full advantage of these tax-advantaged accounts. Even though most U.S. households are eligible to contribute to an IRA, only 14% did so in 2007.

Part of the problem: Nearly a third of adults aren't sure whether they're eligible, and 40% don't know you can have an IRA and a 401(k) at the same time, says a recent AARP survey.

The fact is, between traditional, nondeductible, and the Roth IRA, almost anyone can contribute to at least one type of IRA.

Source CNNMoney.com