As preparations for Sunday's Castro Street Fair wind up, 20 bronze sidewalk plaques are in place to guide pedestrians on a stroll through queer history. The Rainbow Honor Walk is a growing monument along the streets of San Francisco honoring LGBT pioneers. Rainbow Honor Walk co-founder David Perry is Eric Jansen's guest on Out in the Bay, 7pm Thursday . We also hear Steven Short's feature on “The Queer Past Becomes Present,” an ongoing exhibit at the GLBT History Museum on 18th Street, also in