Preserve your emergency saving with muni funds

For example, this one:

Wells Fargo Advantage Ult S/T Mun In Inv (SMUAX)

The investment seeks current income exempt from federal income tax consistent with capital preservation. The fund normally invests at least 80% of assets in municipal securities that pay interest exempt from federal income tax, but not necessarily the federal alternative minimum tax (AMT). It invests up to 20% of assets in securities that pay interest subject to federal income taxes, including federal AMT. The fund invests up to 10% of assets in below investment-grade municipal securities. The fund's average effective maturity is one year or less.

Total Expense Ratio:0.72%

The fund can be bought and sold any time without any fees.