Your 401k or 403b might offer a "stable value" fund or, a "guaranteed investment contract," also known as a "GIC."  They are offered by insurance companies and really invest like a money market or bond fund.  IRA accounts don't have access to these investments, although using a CD or bond fund will be very similiar.

Here's a recap from USAToday:

But amid the gloom, you may detect a ray of sunshine: your plan's stable value fund. These funds, which are offered by most large 401(k) plans, were up an average of 5.2% through September, according to the Stable Value Investment Association.

Like bond funds, stable value funds typically invest in corporate and government bonds. In addition, though, they buy contracts from banks and insurance companies, known as wrappers, that guarantee the principal and accumulated interest even if the underlying investments decline in value.

Stable value funds invest in high-quality bonds with an average maturity of 2.8 years, says Gina Mitchell, president of the Stable Value Investment Association. This enables them to deliver better returns than money market funds, which typically invest in fixed-income securities that mature in 30 to 90 days, she says.