Grammar lessons often are associated with high school drudgery--diagramming sentences and memorizing obscure rules in between passing notes in English class--but an Arizona technical writer has turned the seemingly dry subject into a popular podcast. Mignon Fogarty, the woman behind <A HREF="http://www.cnn.com/2007/TECH/internet/01/22/grammar.girl/index.html">Grammar Girl's Quick & Dirty Tips for Better Writing,</A> has been explaining the finer points of commas, colons and split infinitives since July. Fogarty said she got the idea for the podcast, sort of an Internet radio show, during a California vacation. The show is currently the 47th most popular podcast on Apple's iTunes service, right behind "Merriam-Webster's Word of the Day." It has been as high as number two, Fogarty said. She said the shows have been downloaded more than 1.3 million times.