Blow dry bars are growing in number, and now there’s another “bar” in the hair salon sector. The Smooth Bar is San Diego claims to be the first salon in the nation to specialize entirely on hair-smoothing treatments. “Smoothing treatments are now the largest single service growth area in the salon industry, with a rapidly expanding customer base,” explained Stacey Zayas, creator of The Smooth Bar. “Smooth hair is a style that just doesn't seem to come or go – it's al...