Well, I jacked up the car during lunch to check for any extreme play and didn't find any. Power-washed all the grime off under the car and gave'er a good greasin but the sound remains...somehow I didn't think it was going to be that easy...

Any way to know for sure if the boots still have grease in them or if they've dried out?

Also, is checking for lateral play on the tires the best way to check on the wheel bearings? A friend of mine is convinced that replacing my 1 yr old rear bearings is the way to go. I'd rather not have to go through the pain of getting those bearings off again...I think getting a root canal would be more pleasant...