The sneezing could be an upper respiratory infection. The drooling could be a number of things from a loose tooth, nausea, ingesting something toxic, etc. My main concern is his breathing. If he is actually gasping he needs to see a vet tonight. What color are his gums? If they are blueish or purplish at all then he is not moving enough in and needs to see a vet asap. Is he eating normally? Using the litter box normally? Look in his mouth and be sure you don't see anything caught in here. Smell his breath and see if it smells unusual. Is he an inside only cat? The dust spores from Valley Fever can get inside your house. More common signs of it in pets would be limping and sores on the body. Here is a good link on it:
http://www.vfce.arizona.edu/VFID-symp.htm
Edited by jwarder on January 27 2006 at 10:17 PM
If my answer was helpful please click the green accept button My answer should not take the place of a Vet's diagnosis when needed. Positive feedback is most welcome and a bonus-though not required-is greatly appreciated no matter how small.