Have you got the En-Oh-Two Blues?  Are you struggling to understand federal modeling guidance that seems to change weekly?  Well, we've got the answer – take two aspirin and call us in the morning.  Or, you can join us for a lively discussion of the dispersion modeling challenges posed by the new federal air quality standards for nitrogen dioxide, sulfur dioxide, and fine particulates over the last few years.  Our speakers include Leland Villalvazo of the San Joaquin Valley APCD who has spearheaded the efforts of California air districts to establish consistent modeling guidelines for dealing with these new standards; Pat Sullivan of SCS Engineers; and Gary Rubenstein of Sierra Research.