The following query searches for images about the Tour de France:
http://boss.yahooapis.com/ysearch/images/v1/tour+de+france?format=xmlThe following query searches for images about dog shows, and specifies a dimension for the results of wallpaper:
http://boss.yahooapis.com/ysearch/images/v1/dog+show?format=xml&img.dimensions=wallpaper