Once upon a time, on radios very much like those commonly sold today, DJs had unique personas that set them apart from everyone else on the airwaves. But such individuality has been on the wane since corporations discovered that air personalities, like nuts and bolts, cost less when they're interchangeable. So praise be for Gregg Stone, aka Uncle Nasty, whose gruff tone, tough-guy lingo and deep knowledge of hard rock and heavy metal continue to distinguish KBPI on weekday afternoons.