Some info. from Bondi Band's website:
Their goal is to "offer comfy, colorful, and creative headbands to fit every lifestyle and personality." They have bands for men, women, kids, AND dogs!
"By using stretchy and breathable material, we allow Bondi Bands to fit virtually every head size comfortably and fashionably."
They even donate 10% of their pretax profits to charity! For 2009 they chose the Dana-Farber Cancer Institute.