In most communities, real estate property taxes are based upon an estimate of your home's value. If home prices have dropped since you bought your home, you may be able to appeal your assessment and enjoy a reduction in the property taxes that you're required to pay.
Contact your local Assessor's Office to inquire as to the local procedure for appealing your property taxes. Generally, the process involves providing comparable sales data in writing to the assessor to prove the reduced value of your home. If you need help with this exercise, contact the real estate agent who sold you the home. Just be aware that your agent may want to make you feel as though your home hasn't decreased as much in value in order to make you (and perhaps himself) feel better. Explain that you're trying to save money on your property taxes and need comparables that sold for less than you paid for your house.