Regular readers of our barbecue chronicles will remember David Woo, pictured below, the great wheelman on our East Texas tour in February. Newspapers and websites across the country picked up the story, which lauded him, and his GPS, for helping us navigate rural roads. On our Fort Worth Tour in April, however, Woo’s GPS failed him. He followed its instructions to the letter and wound up trapped in the middle of the packed Downtown Arts Festival. Some of us, by luck, detoured around downtown. “I forgot about the festival,” Woo said as he, and those in a couple other tour…