Well, the weather is so much cooler up here in Virginia (contrary to what the locals think) that I hadn't even noticed our air conditioner wasn't working as well as it ought to.  Leeanne started to complain that it was a little warm, so I checked the air filters.  Turns out there are two of them.  I'm not sure why, because there is only one unit, but sure enough, they were quite dirty.  If you don't have pets, then you probably don't understand.  At any rate, I was able to dust them off with compressed air and pop em back in, good as new.