if you own a property with an aging hvac system, you may want to consider replacing it this year.
effective jan? 2006, minimum effiencey standards will change from 10 to 13 seer. a thirteen seer system will probably be about 20-40% higher in price than the 10.
(and who couldn't use the writeoff next year?)
i wouldn't recommend this for any other reason, than it being an investment property.