Women already earn less than men 80 cents on the dollar, at last count. But when it comes to saving for retirement, over time that 20-cent gap could easily grow into a $260,000 chasm.

Consider the findings of the report released earlier this week by the Government Accountability Office. Women who rise to management ranks earn an average of 81 cents for every dollar a male manager earns; women in non-manager jobs earn 80.2 cents. What you don t earn, you can t save, so over a lifetime of work, that gap can lead to a significant retirement shortfall. It gets worse: Women work 27 years, compared to 40 years for men, but live longer, which means they have fewer working years to save for a longer retirement.

For example, if a woman saves 10% of her income each year for 35 years (and gets 2% annual raises), it s quite possible she would retire with $260,000 less in retirement savings than a man with the same savings patterns, says Lauren Locker, founder of Locker Financial Services in Little Falls, N.J. Add to that the fact that her Social Security checks will be much lower than a man s, because they re based on a calculation using a worker s highest 35 years of income, and it s easy to see why the income disparity is a huge factor in how much [money] women will have in retirement, Locker says.

That means that women need a different strategy for saving for retirement than men. Until the wage gap closes, women have to save more and start saving earlier which is about as fair as making 80 cents on the dollar. To make up for the wage gap, many financial advisors recommend that women save 10-15% of their income in their 20s, then raise the percentage as they get older, until they re saving 30% or more in their 60s. For men, on the other hand, planners recommend simply a flat 10%.

Here are five other ways women can shore up their retirement funds.

Open a spousal IRA

Over a lifetime, women spend 13 fewer years in the workforce than men, according to the Women s Institute for a Secure Retirement. And in those non-working years, many women ignore their retirement savings; then, when they return, they ve often lost ground on salary, so their savings continue to fall behind.

It doesn't have to be that way. During those non-working years, a woman can make tax-deductible contributions of up to $5,000 (or $6,000 for people 50 or older) to a spousal IRA, as long as the working spouse has enough earned income to cover the contribution and the couple files their taxes jointly.

Consider an annuity

Running out of money may be the biggest economic risk of retirement. Because women live longer, they need their income to last longer; they also often outlive their spouse, which means paying for the final years on one retirement income. An income annuity, which turns a lump sum of money into a stream of payments for life, can secure a minimum level of income forever.

Annuities, which are sold by insurance companies, have gotten a bad rap. But unlike variable annuities, which are investment accounts, lifetime income annuities are purchased with a single payment say, the balance of your 401(k) when you retire and then throw off regular paychecks as long as you live. For example, by buying a $178,000 annuity, a 65-year-old woman could secure $1,000 a month in lifetime income. It may sound like a lot up front, but the initial amount is recouped after 15 years of payments.

But beware: Almost all annuities have fees that are too high, says Mitchell Reiner, a CFP at Capital Investment Advisors. For a primer on how to decipher annuity fees, click here. And to find a suitable annuity, consult your financial advisor and check out SmartMoney.com s annuity ratings.

Get what you're entitled to

About 45% of marriages in the United States end in divorce, according to DivorceMag.com. And yet, many divorced women don t realize they may be entitled to part of their exes retirement and Social Security benefits. To collect a spouse s Social Security, you must have been married for 10 years or more and now be 62 or older, unmarried, and not eligible for a greater benefit based on your own work record. If you qualify, you can get as much as your ex-husband's full Social Security benefit for the rest of your life, as long as you don t remarry, says Reiner. To collect on a private-sector plan like a 401(k), you will need a Qualified Domestic Relations Order (QDRO), which highlights your right to receive all or some of the benefits, and contact the plan administrator for further details.

Weigh employee benefits

When you move from one employer to another, consider the big picture, beyond salary and bonuses. "Look closely at retirement, advises Mark Miller, author of The Hard Times Guide to Retirement Security." Beyond a 401(k) match and profit-sharing plans, ask about perks like retiree health benefits. Though few companies still offer it (the government is a major exception), it s tremendously valuable. In 2009, a typical 65-year-old female retiree could need as much as $450,000 in savings to cover health care, according to the Employee Benefit Research Institute. Learn more about retiree health benefits here.

Take the "joint and survivor" pension option

If your spouse is one of the estimated 19.4 million active pension participants in the U.S., he ll likely need to choose how to take the benefit in retirement. The single life option provides a fixed amount of money but when he dies, the pension payments stop. Nearly one-third of men choose this option, despite the fact that it might jeopardize their spouses economic security if they become widowed, according to a study by the Urban Institute.

The joint and survivor pension option lets a spouse continue to receive payments for as long as she lives. It helps [women] guarantee a stream of income, says Wes Moss, chief investment strategist at Capital Investment Advisors. There s a catch, of course. The monthly payout is lower. For example, a 65-year-old retiring man who would receive $1,900 per month with the single life option would get just $1,500 per month under the joint and survivor option. The exact difference depends on the ages of both spouses, years worked and income, among other things.