Federal, state, and utility incentives for energy efficiency can be found at www.dsireusa.org.
The American Recovery and Reinvestment Act of 2009 provides funds to the states for appliance rebate programs. See www.energysavers.gov.
For more details on current federal tax credits, see www.energysavers.gov.
Many utilities offer rebates for energy-efficient appliances. See the details for your state at www.dsireusa.org.
Energy Star has a rebate-locator tool, searchable by zip code, which includes programs offered by its partners (which include some, but not all, utilities and appliance manufacturers). See www.energystar.gov