Homeowners looking to replace their old ugly drafty windows
can receive up to an $1500 dollar tax credit on their Federal Income taxes. The American Recovery and Reinvestment Act of 2009 (stimulus bill) allows for a credit of 30% of your costs for the windows to a maximum of $1500. Only the cost of the windows are allowed. Not the installation fees, etc.
Also the windows have to meet certain energy efficiency ratings. They must have a U-Factor and a Solar Heat Gain Coefficient, or SHGC of equal or less than 0.30 in all climate zones in the U.S. Be sure to check the rating label on all windows before buying to be sure it will qualify. One would be wise to save these labels if the IRS should come a calling. The tax credit runs until the end of 2010.
If you have an older home such as mine (1979) you may want to take a further look at this.