LOOSE CHANGE: For its own brand of truth in advertising, we must applaud Dorson's Furniture for a billboard that long graced a westerly corner of First Avenue, near the Catalina foothills. It read: "For more than 20 years, Dorson's has provided high-quality furniture at low prices." As the traffic inched closer, if you were still looking to see which satisfied consumer generously went on record to praise the local business, you'd see in slightly smaller type the name Bob Dorson. Well, Bob, perhaps you were ahead of your time. (A going-out-of-business sale a few months back suggests some kind of sea change.) But if there's one Emersonian concept this paper has amusedly embraced over the years, it's that if you don't see shame in being biased, it isn't there.