Savers have traditionally had to settle for certificates of deposit with lower interest rates in exchange for quick access to cash without a penalty.

But now rates for no-penalty CDs are just as good, if not better, than those for traditional ones.

"Banks are making the no-penalty CDs more appealing and getting those deposits today, versus not getting those deposits" at all, says Greg McBride, senior financial analyst at Bankrate.com.

Ally Bank's nine-month no-penalty CD recently had an annual yield of 1.85%, compared with 1.55% for its regular nine-month CD, according to the bank's site.

Bank of America was recently offering a nine-month no-penalty CD, called a Risk-Free CD, with an annual yield of 0.7%. Its standard CDs, with terms between six and 11 months, had a 0.5% yield.

While there's no penalty for early withdrawals, some banks do require that people wait 90 days after setting up a CD before withdrawing money. So you should still factor in the time horizon for when you may need the cash, Mr. McBride says.

A no-penalty CD could pay off if interest rates rise from today's very low levels, by making it easy for you to switch. "People who are locking in a longer-term CD [at current rates] are making a big mistake," says Marc Schindler, a certified financial planner in Bellaire, Texas.