I have always been a beliver in barometric pressure changes affecting the feeding "mood" of fish. However in this months
Saltwater Fly Fishing (nice front cover this month too) there was an article on this. The article mentiond that due to the density of water as compaired to air, a 6 inch wave creates more of a pressure change than any barometric change could and in a fraction of the time. The article basically said the barometer affecting fish was basically bunk.
I still think fishing is better on a falling or low barometer. Maybe its a confidence thing.
Link to magazine subscription page if your intrested, usually has some good stuff.
http://www.flyfishingmagazines.com/magazine_sff.shtml